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The endocrine system is made up of glands that produce and secrete hormones, chemical substances produced in the body that regulate the activity of cells or organs. These hormones regulate the body's growth, metabolism (the physical and chemical processes of the body), and sexual development and function.
The endocrine system refers to the collection of glands of an organism that secrete hormones directly into the circulatory system to be carried towards distant target organs. The major endocrine glands include the pineal gland, pituitary gland, pancreas, ovaries, testes, thyroid gland, parathyroid gland,hypothalamus, gastrointestinal tract and adrenal glands. The endocrine system is in contrast to the exocrine system, which secretes its hormones to the outside of the body using ducts. The endocrine system is an information signal system like the nervous system, yet its effects and mechanism are classifiably different. The endocrine system's effects are slow to initiate, and prolonged in their response, lasting from a few hours up to weeks. The nervous system sends information very quickly, and responses are generally short lived. In vertebrates, the hypothalamus is the neural control center for all endocrine systems. The field of study dealing with the endocrine system and its disorders is endocrinology, a branch of internal medicine.[1] Special features ofendocrine glands are, in general, their ductless nature, their vascularity, and commonly the presence of intracellular vacuoles or granules that store their hormones. In contrast, exocrine glands, such as salivary glands, sweat glands, and glands within the gastrointestinal tract, tend to be much less vascular and have ducts or a hollow lumen.
In addition to the specialized endocrine organs mentioned above, many other organs that are part of other body systems, such as bone, kidney, liver, heartand gonads, have secondary endocrine functions. For example, the kidney secretes endocrine hormones such as erythropoietin and renin. Hormones can consist of either amino acid complexes, steroids, eicosanoids, leukotrienes, or prostaglandins.[1]The major glands that make up the human endocrine system include the:
| Secreted hormone | From cells | Effect |
|---|---|---|
| Melatonin | Pinealocytes | Antioxidant Monitors the circadian rhythm including induction of drowsiness and lowering of the core body temperature |
The pituitary gland (or hypophysis) is an endocrine gland about the size of a pea and weighing 0.5 grams (0.018 oz) in humans. It is a protrusion off the bottom of the hypothalamus at the base of thebrain, and rests in a small, bony cavity (sella turcica) covered by a dural fold (diaphragma sellae). The pituitary is functionally connected to the hypothalamus by the median eminence via a small tube called the infundibular stem or pituitary stalk. .[citation needed]
| Secreted hormone | Abbreviation | From cells | Effect |
|---|---|---|---|
| Growth hormone (somatotropin) | GH | Somatotrophs | Stimulates growth and cell reproduction Stimulates Insulin-like growth factor 1 release from liver |
| Thyroid-stimulating hormone (thyrotropin) | TSH | Thyrotrophs | Stimulates thyroxine (T4) and triiodothyronine (T3) synthesis and release from thyroid gland Stimulates iodine absorption by thyroid gland |
| Adrenocorticotropic hormone (corticotropin) | ACTH | Corticotrophs | Stimulates corticosteroid (glucocorticoid and mineralcorticoid) and androgen synthesis and release from adrenocortical cells |
| Beta-endorphin | – | Corticotrophs | Inhibits perception of pain |
| Follicle-stimulating hormone | FSH | Gonadotrophs | In females: Stimulates maturation of ovarian follicles in ovary In males: Stimulates maturation of seminiferous tubules In males: Stimulates spermatogenesis In males: Stimulates production of androgen-binding protein from Sertoli cells of the testes |
| Luteinizing hormone | LH | Gonadotrophs | In females: Stimulates ovulation In females: Stimulates formation of corpus luteum In males: Stimulates testosterone synthesis from Leydig cells (interstitial cells) |
| Prolactin | PRL | Lactotrophs | Stimulates milk synthesis and release from mammary glands Mediates sexual gratification |
| Melanocyte-stimulating hormone | MSH | Melanotropes in the Pars intermedia of the Anterior Pituitary | Stimulates melanin synthesis and release from skin/hair melanocytes |
| Stored hormone | Abbreviation | From cells | Effect |
|---|---|---|---|
| Oxytocin | Magnocellular neurosecretory cells | In females: uterine contraction during birthing, lactation (letdown reflex) when nursing | |
| Vasopressin (antidiuretic hormone) | ADH or AVP | Parvocellular neurosecretory neurons | Increases water permeability in the distal convoluted tubule and collecting duct of nephrons, thus promoting water reabsorption and increasing blood volume |
Oxytocin and anti-diuretic hormone are not secreted in the posterior lobe, merely stored.
| Secreted hormone | Abbreviation | From cells | Effect |
|---|---|---|---|
| Triiodothyronine | T3 | Thyroid epithelial cell | (More potent form of thyroid hormone) Stimulates body oxygen and energy consumption, thereby increasing the basal metabolic rate Stimulates RNA polymerase I and II, thereby promoting protein synthesis |
| Thyroxine (tetraiodothyronine) | T4 | Thyroid epithelial cells | (Less active form of thyroid hormone) (Acts as a prohormone to triiodothyronine) Stimulates body oxygen and energy consumption, thereby increasing the basal metabolic rate Stimulates RNA polymerase I and II, thereby promoting protein synthesis |
| Calcitonin | Parafollicular cells | Stimulates osteoblasts and thus bone construction Inhibits Ca2+ release from bone, thereby reducing blood Ca2+ |
| Secreted hormone | Abbreviation | From cells | Effect |
|---|---|---|---|
| Gastrin (Primarily) | G cells | Secretion of gastric acid by parietal cells | |
| Ghrelin | P/D1 cells | Stimulate appetite. | |
| Neuropeptide Y | NPY | Increased food intake and decreased physical activity. It can be associated with obesity. | |
| Somatostatin | D cells | Suppress release of gastrin, cholecystokinin (CCK), secretin, motilin, vasoactive intestinal peptide(VIP), gastric inhibitory polypeptide (GIP), enteroglucagon Lowers rate of gastric emptying Reduces smooth muscle contractions and blood flow within the intestine.[2] | |
| Histamine | ECL cells | stimulate gastric acid secretion | |
| Endothelin | X cells | Smooth muscle contraction of stomach[3] |
| Secreted hormone | From cells | Effect |
|---|---|---|
| Secretin | S cells | Secretion of bicarbonate from liver, pancreas and duodenal Brunner's glands Enhances effects of cholecystokinin, stops production of gastric juice |
| Cholecystokinin | I cells | Release of digestive enzymes from pancreas Release of bile from gallbladder, hunger suppressant |
| Secreted hormone | Abbreviation | From cells | Effect |
|---|---|---|---|
| Insulin-like growth factor (or somatomedin) (Primarily) | IGF | Hepatocytes | insulin-like effects regulate cell growth and development |
| Angiotensinogen and angiotensin | Hepatocytes | vasoconstriction release of aldosterone from adrenal cortex dipsogen. | |
| Thrombopoietin | THPO | Hepatocytes | stimulates megakaryocytes to produce platelets[4] |
| Hepcidin | Hepatocytes | inhibits intestinal iron absorption and iron release by macrophages |
The pancreas is a mixocrine gland and it secretes both enzymes and hormones.
| Secreted hormone | From cells | Effect |
|---|---|---|
| Insulin (Primarily) | ? Islet cells | Intake of glucose, glycogenesis and glycolysis in liver and muscle from blood. Intake of lipids and synthesis of triglycerides in adipocytes. Other anabolic effects |
| Glucagon (Also Primarily) | ? Islet cells | Glycogenolysis and gluconeogenesis in liver. Increases blood glucose level. |
| Somatostatin | ? Islet cells | Inhibit release of insulin[5] Inhibit release of glucagon[5] Suppress the exocrine secretory action of pancreas. |
| Pancreatic polypeptide | PP cells | Self regulate the pancreas secretion activities and effect the hepatic glycogen levels. |
| Secreted hormone | From cells | Effect |
|---|---|---|
| Renin (Primarily) | Juxtaglomerular cells | Activates the renin-angiotensin system by producing angiotensin I of angiotensinogen |
| Erythropoietin (EPO) | Extraglomerular mesangial cells | Stimulate erythrocyte production |
| Calcitriol (1,25-dihydroxyvitamin D3) | Proximal tubule cells | Active form of vitamin D3 Increase absorption of calcium and phosphate from gastrointestinal tract and kidneys inhibit release of PTH |
| Thrombopoietin | stimulates megakaryocytes to produce platelets[4] |
| Secreted hormone | From cells | Effect |
|---|---|---|
| Glucocorticoids (chiefly cortisol) | zona fasciculata and zona reticularis cells | Stimulates gluconeogenesis Stimulates fat breakdown in adipose tissue Inhibits protein synthesis Inhibits glucose uptake in muscle and adipose tissue Inhibits immunological responses (immunosuppressive) Inhibits inflammatory responses (anti-inflammatory) |
| Mineralocorticoids (chiefly aldosterone) | Zona glomerulosa cells | Stimulates active sodium reabsorption in kidneys Stimulates passive water reabsorption in kidneys, thus increasing blood volume and blood pressure Stimulates potassium and H+ secretion into nephron of kidney and subsequent excretion |
| Androgens (including DHEA andtestosterone) | Zona fasciculata and Zona reticularis cells | In males: Relatively small effect compared to androgens from testes In females: masculinizing effects |
| Secreted hormone | From cells | Effect |
|---|---|---|
| Adrenaline (epinephrine) (Primarily) | Chromaffin cells | Fight-or-flight response:
|
| Noradrenaline (norepinephrine) | Chromaffin cells | Fight-or-flight response:
|
| Dopamine | Chromaffin cells | Increase heart rate and blood pressure |
| Enkephalin | Chromaffin cells | Regulate pain |
| Secreted hormone | From cells | Effect |
|---|---|---|
| Androgens (chiefly testosterone) | Leydig cells | Anabolic: growth of muscle mass and strength, increased bone density, growth and strength, Virilizing: maturation of sex organs, formation of scrotum, deepening of voice, growth of beard andaxillary hair. |
| Estradiol | Sertoli cells | Prevent apoptosis of germ cells[6] |
| Inhibin | Sertoli cells | Inhibit production of FSH |
| Secreted hormone | From cells | Effect |
|---|---|---|
| Progesterone | Granulosa cells, theca cells | Support pregnancy:[7]
Other:
|
| Androstenedione | Theca cells | Substrate for estrogen |
| Estrogens (mainly estradiol) | Granulosa cells | Structural:
Protein synthesis:
Fluid balance:
Gastrointestinal tract:
Melanin:
Cancer:
Lung function: |
| Inhibin | Granulosa cells | Inhibit production of FSH from anterior pituitary |
| Secreted hormone | Abbreviation | From cells | Effect |
|---|---|---|---|
| Progesterone (Primarily) | Support pregnancy:[7]
Other effects on mother similar to ovarian follicle-progesterone | ||
| Estrogens (mainly Estriol) (Also Primarily) | Effects on mother similar to ovarian follicle estrogen | ||
| Human chorionic gonadotropin | HCG | Syncytiotrophoblast | Promote maintenance of corpus luteum during beginning of pregnancy Inhibit immune response, towards the human embryo. |
| Human placental lactogen | HPL | Syncytiotrophoblast | Increase production of insulin and IGF-1 Increase insulin resistance and carbohydrate intolerance |
| Inhibin | Fetal Trophoblasts | Suppress FSH |
| Secreted hormone | Abbreviation | From cells | Effect |
|---|---|---|---|
| Prolactin | PRL | Decidual cells | milk production in mammary glands |
| Relaxin | Decidual cells | Unclear in humans and animals |
| Secreted hormone | Abbreviation | From cells | Effect |
|---|---|---|---|
| Parathyroid hormone | PTH | Parathyroid chief cell | Calcium:
|
| Secreted hormone | From cells | Effect |
|---|---|---|
| Calcidiol (25-hydroxyvitamin D3) | Inactive form of vitamin D3 |
| Secreted hormone | Abbreviation | From cells | Effect |
|---|---|---|---|
| Atrial-natriuretic peptide | ANP | Cardiac myocytes | Reduce blood pressure by: reducing systemic vascular resistance, reducing blood water, sodium and fats |
| Brain natriuretic peptide | BNP | Cardiac myocytes | (To a lesser degree than ANP) reduce blood pressure by: reducing systemic vascular resistance, reducing blood water, sodium and fats |
| Secreted hormone | From cells | Effect |
|---|---|---|
| Thrombopoietin | liver and kidney cells | stimulates megakaryocytes to produce platelets[4] |
In 1998, skeletal muscle was identified as an endocrine organ[12] due to its now well-established role in the secretion of myokines.[12][13] The use of the term myokine to describe cytokines and other peptides produced by muscle as signalling molecules was proposed in 2003.[14]
Signalling molecules released by adipose tissue are referred to as adipokines.
| Secreted hormone | From cells | Effect |
|---|---|---|
| Leptin (Primarily) | Adipocytes | decrease of appetite and increase of metabolism. |
| Estrogens[15] (mainly Estrone) | Adipocytes |
The human endocrine system consists of several systems that operate via feedback loops. Several important feedback systems are mediated via the hypothalamus and pituitary.[16]
Extensive bidirectional interactions exist between the endocrine system and the immune system.[17] Cortisol has major immunosuppressive effects,[18][19] and dopamine has immunomodulatory functions.[20] On the other hand, cytokines produced during inflammation activate the HPA axis at all three levels, sensible to negative feedback.[21] Moreover, cytokines stimulate hepcidin release from the liver, which is eventually responsible for the anemia of chronic disease.[22]
The typical mode of cell signaling in the endocrine system is endocrine signaling. However, there are also other modes, i.e., paracrine, autocrine, and neuroendocrine signaling. Purely neurocrine signaling between neurons, on the other hand, belongs completely to the nervous system.
It occurs between adjacent cells that possess broad patches of closely opposed plasma membrane linked by transmembrane channels known as connexons. The gap between the cells can usually be between only 2 and 4 nm.[citation needed]
Endocrinopathies are classified as primary, secondary, or tertiary. Primary endocrine disease inhibits the action of downstream glands. Secondary endocrine disease is indicative of a problem with the pituitary gland. Tertiary endocrine disease is associated with dysfunction of the hypothalamus and its releasing hormones.[citation needed]Diseases of the endocrine system are common,[24] including conditions such as diabetes mellitus, thyroid disease, and obesity. Endocrine disease is characterized by irregulated hormone release (a productive pituitary adenoma), inappropriate response to signaling (hypothyroidism), lack of a gland (diabetes mellitus type 1, diminished erythropoiesis in chronic renal failure), or structural enlargement in a critical site such as the thyroid (toxic multinodular goitre). Hypofunction of endocrine glands can occur as a result of loss of reserve, hyposecretion, agenesis, atrophy, or active destruction. Hyperfunction can occur as a result of hypersecretion, loss of suppression, hyperplastic or neoplastic change, or hyperstimulation.
As the thyroid, and hormones have been implicated in signaling distant tissues to proliferate, for example, the estrogen receptor has been shown to be involved in certain breast cancers. Endocrine, paracrine, and autocrine signaling have all been implicated in proliferation, one of the required steps of onco
Hormone levels that are too high or too low indicate a problem with the endocrine system. Hormone diseases also occur if your body does not respond to hormones in the appropriate ways. Stress, infection, and changes in the blood's fluid and electrolyte balance can also influence hormone levels, according to the National Institutes of Health.
The most common endocrine disease in the United States is diabetes, a condition in which the body does not properly process glucose, a simple sugar. This is due to the lack of insulin or, if the body is producing insulin, because the body is not working effectively, according to Dr. Jennifer Loh, chief of the department of endocrinology for Kaiser Permanente in Hawaii.
Hormone imbalances can have a significant impact on the reproductive system, particularly in women, Loh explained.
Another disorder, hypothyroidism, occurs when the thyroid gland does not produce enough thyroid hormone to meet the body’s needs. Loh noted that insufficient thyroid hormone can cause many of the body's functions to slow or shut down completely.
Thyroid cancer begins in the thyroid gland and starts when the cells in the thyroid begin to change, grow uncontrollably and eventually form a tumor, according to Loh.
Hypoglycemia, also called low blood glucose or low blood sugar, occurs when blood glucose drops below normal levels. This typically happens as a result of treatment for diabetes when too much insulin is taken. While Loh noted that the condition can occur in people not undergoing treatment for diabetes, such an occurrence is fairly rare.
The hypothalamus (pronounced: hi-po-THAL-uh-mus), a collection of specialized cells that is located in the lower central part of the brain, is the main link between the endocrine and nervous systems. Nerve cells in the hypothalamus control the pituitary gland by producing chemicals that either stimulate or suppress hormone secretions from the pituitary.
Although it is no bigger than a pea, the pituitary (pronounced: puh-TOO-uh-ter-ee) gland, located at the base of the brain just beneath the hypothalamus, is considered the most important part of the endocrine system. It's often called the "master gland" because it makes hormones that control several other endocrine glands.
The production and secretion of pituitary hormones can be influenced by factors such as emotions and changes in the seasons. To accomplish this, the hypothalamus provides information sensed by the brain (such as environmental temperature, light exposure patterns, and feelings) to the pituitary.
The tiny pituitary is divided into two parts: the anterior lobe and the posterior lobe. The anterior lobe regulates the activity of the thyroid, adrenals, and reproductive glands. The anterior lobe produces hormones such as:
The pituitary also secretes endorphins (pronounced: en-DOR-fins), chemicals that act on the nervous system and reduce feelings of pain. In addition, the pituitary secretes hormones that signal the reproductive organs to make sex hormones. The pituitary gland also controls ovulation and the menstrual cycle in women.
The posterior lobe of the pituitary releases antidiuretic(pronounced: an-ty-dy-uh-REH-tik) hormone, which helps control the balance of water in the body. The posterior lobe also produces oxytocin (pronounced: ahk-see-TOE-sin), which triggers the contractions of the uterus in a woman having a baby.
The thyroid (pronounced: THY-royd), located in the front part of the lower neck, is shaped like a bow tie or butterfly and produces the thyroid hormones thyroxine (pronounced: thy-RAHK-sin) andtriiodothyronine (pronounced: try-eye-oh-doe-THY-ruh-neen). These hormones control the rate at which cells burn fuels from food to produce energy.
The production and release of thyroid hormones is controlled bythyrotropin (pronounced: thy-ruh-TRO-pin), which is secreted by the pituitary gland. The more thyroid hormone there is in a person's bloodstream, the faster chemical reactions occur in the body.
Why are thyroid hormones so important? There are several reasons — for example, they help kids' and teens' bones grow and develop, and they also play a role in the development of the brain and nervous system in kids.
Attached to the thyroid are four tiny glands that function together called the parathyroids (pronounced: par-uh-THY-roydz). They release parathyroid hormone, which regulates the level of calcium in the blood with the help of calcitonin (pronounced: kal-suh-TOE-nin), which is produced in the thyroid.
The body also has two triangular adrenal (pronounced: uh-DREE-nul) glands, one on top of each kidney.
The adrenal glands have two parts, each of which produces a set of hormones and has a different function:
The pineal (pronounced: pih-NEE-ul) body, also called the pineal gland, is located in the middle of the brain. It secretes melatonin(pronounced: meh-luh-TOE-nin), a hormone that may help regulate when you sleep at night and when you wake in the morning.
The gonads are the main source of sex hormones. Most people don't realize it, but both guys and girls have gonads.
In guys the male gonads, or testes (pronounced: TES-teez), are located in the scrotum. They secrete hormones called androgens(pronounced: AN-druh-junz), the most important of which istestosterone (pronounced: tess-TOSS-tuh-rone). These hormones tell a guy's body when it's time to make the changes associated withpuberty, like penis and height growth, deepening voice, and growth in facial and pubic hair. Working with hormones from the pituitary gland, testosterone also tells a guy's body when it's time to produce sperm in the testes.
A girl's gonads, the ovaries (pronounced: OH-vuh-reez), are located in her pelvis. They produce eggs and secrete the female hormones estrogen (pronounced: ESS-truh-jen) and progesterone(pronounced: pro-JESS-tuh-rone). Estrogen is involved when a girl begins to go through puberty. During puberty, a girl will experience breast growth, will begin to accumulate body fat around the hips and thighs, and will have a growth spurt. Estrogen and progesterone are also involved in the regulation of a girl's menstrual cycle. These hormones also play a role in pregnancy.
Although the endocrine glands are the body's main hormone producers, some other organs not in the endocrine system — such as the brain, heart, lungs, kidneys, liver, and skin — also produce and release hormones.
The pancreas (pronounced: PAN-kree-us) is also part of the body's hormone-secreting system, even though it is also associated with the digestive system because it produces and secretes digestive enzymes.
The pancreas produces (in addition to others) two important hormones, insulin (pronounced: IN-suh-lin) and glucagon(pronounced: GLOO-kuh-gawn). They work together to maintain a steady level of glucose, or sugar, in the blood and to keep the body supplied with fuel to produce and maintain stores of energy.
Once a hormone is secreted, it travels from the endocrine gland that produced it through the bloodstream to the cells designed to receive its message. These cells are called target cells. Along the way to the target cells, special proteins bind to some of the hormones. These proteins act as carriers that control the amount of hormone that is available for the cells to use.
The target cells have receptors that latch onto only specific hormones, and each hormone has its own receptor, so that each hormone will communicate only with specific target cells that have receptors for that hormone. When the hormone reaches its target cell, it locks onto the cell's specific receptors and these hormone-receptor combinations transmit chemical instructions to the inner workings of the cell.
When hormone levels reach a certain normal amount, the endocrine system helps the body to keep that level of hormone in the blood. For example, if the thyroid gland has secreted the right amount of thyroid hormones into the blood, the pituitary gland senses the normal levels of thyroid hormone in the bloodstream. Then the pituitary gland adjusts its release of thyrotropin, the hormone that stimulates the thyroid gland to produce thyroid hormones.
Another example of this process is parathyroid hormone, which increases the level of calcium in the blood. When the blood calcium level rises, the parathyroid glands sense the change and reduce their secretion of parathyroid hormone. This turnoff process is called a negative feedback system.
Too much or too little of any hormone can be harmful to your body. For example, if the pituitary gland produces too much growth hormone, a teen may grow excessively tall. If it produces too little, a teen may be unusually short. Doctors can often treat problems with the endocrine system by controlling the production of hormones or replacing certain hormones with medication.
Endocrine problems that can affect teens include:
Adrenal insufficiency. This condition occurs when the adrenal glands don't produce enough corticosteroids. The symptoms of adrenal insufficiency may include weakness, fatigue, abdominal pain, nausea, dehydration, and skin changes. Doctors treat adrenal insufficiency with medications to replace corticosteroid hormones.
Type 1 diabetes. When the pancreas fails to produce enough insulin, type 1 diabetes (previously known as juvenile diabetes) occurs. In kids and teens, type 1 diabetes is usually an autoimmune disorder, which means that some parts of the body's immune system attack and destroy the cells of the pancreas that produce insulin. To control their blood sugar levels and reduce the risk of developing diabetes problems, kids and teens with this condition need regular injections of insulin.
Type 2 diabetes. Unlike type 1 diabetes, in which the body can't produce normal amounts of insulin, in type 2 diabetes the body can't respond to insulin normally. Kids and teens with the condition tend to be overweight. Some kids and teens can control their blood sugar level with dietary changes, exercise, and oral medications, but many will need to take insulin injections like people with type 1 diabetes.
Growth hormone problems. Too much growth hormone in kids and teens who are still growing will make their bones and other body parts grow excessively. This rare condition (sometimes called gigantism) is usually caused by a pituitary tumor and can be treated by removing the tumor. The opposite can happen when a kid or teen has a pituitary glad that doesn't produce enough growth hormone. Doctors may treat these growth problems with medication.
Hyperthyroidism. Hyperthyroidism is a condition in which the levels of thyroid hormones in the blood are very high. In kids and teens, the condition is usually caused by Graves' disease, an immune system problem that causes the thyroid gland to become very active. Doctors may treat hyperthyroidism with medications, surgery, or radiation treatments.
Hypothyroidism. Hypothyroidism is a condition in which the levels of thyroid hormones in the blood are very low. Thyroid hormone deficiency slows body processes and may lead to fatigue, a slow heart rate, dry skin, weight gain, and constipation. Kids and teens with this condition may also grow more slowly and reach puberty at a later age. Hashimoto's thyroiditis is an immune system problem that often causes problems with the thyroid and blocks the production of thyroid hormone. Doctors often treat this problem with medication.
Precocious puberty. If the pituitary glands release hormones that stimulate the gonads to produce sex hormones too early, some kids may begin to go through puberty at a very young age. This condition is called precocious puberty. Kids and teens who are affected by precocious puberty can be treated with medication that will help them develop at a normal rate.
Diabetes mellitus is the most common endocrine disorder and occurs when the pancreas either does not produce sufficient insulin or the body cannot use the available insulin. Symptoms of both type 1 and type 2 diabetes include:
Acromegaly is a disorder in which the pituitary gland overproduces growth hormone. This leads to symptoms of overgrowth, especially of the hands and feet. Symptoms of acromegaly include:
Addison’s disease is characterized by decreased production of cortisol and aldosterone due to adrenal gland damage. Common symptoms of Addison’s disease include:
Cushing’s syndrome arises from excess cortisol, produced by the adrenal glands. Symptoms of Cushing’s syndrome include:
Graves’ disease is a type of hyperthyroidism resulting in excessive thyroid hormone production. Common symptoms of Graves’ disease include:
Hashimoto’s thyroiditis, or autoimmune thyroiditis, is a condition in which the thyroid is targeted by the immune system, leading to hypothyroidism and low production of thyroid hormone. Often, Hashimoto’s thyroiditis is symptomless, but symptoms can include:
Hyperthyroidism is a condition characterized by an overactive thyroid gland. Common symptoms of hyperthyroidism include:
Hypothyroidism is a condition in which the thyroid is underactive and produces too little thyroid hormone. Often, hypothyroidism can be symptomless or very mild. Common symptoms of hypothyroidism include:
Prolactinoma arises when a dysfunctional pituitary gland makes excess prolactin hormone, which functions in the production of breast milk. Excess prolactin can lead to symptoms such as:
In some cases, endocrine disorders can be life threatening. Seek immediate medical care (call 911) if you, or someone you are with, have any of these serious symptoms that might indicate a life-threatening condition including:
A number of factors are believed to cause endocrine disorders. Types and causes of endocrine disorders include:
Acromegaly, an overproduction of growth hormone, and prolactinoma, an overproduction of prolactin hormone, resulting from damage to the pituitary gland
Addison’s disease and Cushing’s syndrome, disorders relating to changes in levels of hormones produced by the adrenal glands
Diabetes mellitus, which arises when the pancreas does not produce sufficient insulin or when the body cannot respond to the insulin that is present
Environmental or nutritional factors, such as a lack of iodine in hypothyroidism, which can affect hormone production
Genetic factors, which may play a role in endocrine disorders, especially with diabetes and other disorders, such as autoimmune thyroiditis, or Hashimoto’s thyroiditis
Hyperthyroidism (overactive thyroid), hypothyroidism (underactive thyroid), Graves’ disease (a type of hyperthyroidism resulting in excessive thyroid hormone production), and Hashimoto’s thyroiditis (autoimmune disease resulting in hypothyroidism), all resulting from problems with the thyroid gland
Tumors, since the underlying cause of the endocrine disorder can be linked to a growth or tumor of the gland
In many cases, the exact cause of a particular endocrine disorder is not known. Often, hormones interact with each other, so symptoms of a particular endocrine disorder may be nonspecific. It is important to seek medical evaluation if you believe you may have an endocrine disorder, as direct assessment of hormone levels may help find and fix the underlying cause of hormone imbalance.
A number of factors increase the risk of developing endocrine disorders. Not all people with risk factors will develop endocrine disorders. Risk factors for endocrine disorders include:
Elevated cholesterol levels
Family history of endocrine disorder
Inactivity
Personal history of autoimmune disorders, such as diabetes
Poor diet
Pregnancy (in cases such as hyperthyroidism)
Recent surgery, trauma, infection, or serious injury
While many endocrine disorders are inherited or arise for unknown reasons, some may be related to modifiable lifestyle factors. You may be able to lower your risk of certain endocrine disorders, such as hypothyroidism, by:
Eating a balanced, healthy diet
Living a healthy lifestyle, including regular physical activity
Medicines used to treat endocrine disorders
The leaflets in this section are authored by an experienced
pharmacist. Pharmacists are experts in medicines. The medicines in this section
include those which act on the endocrine glands. Endocrine glands release
hormones (chemicals) into the blood and include the thyroid, pancreas,
pituitary, ovaries and testes. Many of the medicines in this section are
different types of treatment used in diabetes, but there are also medications
for the thyroid (levothyroxine and carbimazole). They include insulin, metformin
and gliclazide as well as the newer treatments like sitagliptin and
liraglutide. If you've ever thought "Who shouldn't take metformin?",
"How do I take my prednisolone?", "How do I get the most from my
insulin treatment?" or "What problems can bromocriptine cause?"
information leaflets in this section will have answers for you.
In many cases, endocrine disorders may be symptomless or mild enough to not require treatment. Symptoms can arise from excess hormone production or a hormone deficiency. When symptoms of endocrine disorders are bothersome, they can generally be treated by correcting the hormone imbalance. This is often done by means of synthetic hormone administration. In cases such as prolactinoma, where a noncancerous tumor is responsible for symptoms, surgery or radiation therapy may be used. Often, diagnosis and treatment of the underlying cause of the endocrine disorder will resolve the symptoms.
While most endocrine disorders are mild and slow to progress, certain endocrine disorders can lead to complications over time as unbalanced hormonal signaling affects normal body processes. In cases of Addison’s disease and hypothyroidism in particular, acute attacks or crises can have serious complications. Diabetes can also have potentially life-threatening complications. Complications of untreated or poorly controlled endocrine disorders can be serious, even life threatening in some cases. You can help minimize your risk of serious complications by following the treatment plan you and your health care professional design specifically for you. Complications of certain endocrine disorders include:
