The endocrine system is a network of glands that produce and release hormones. These hormones help control many important body functions, including the body's ability to change calories into energy that powers cells and organs. The endocrine system affects how your heart beats, how your bones and tissues grow, and even your ability to make a baby.
Disorders of the endocrine system happen if your hormone levels are too high or too low, or if your body doesn't respond to hormones in the expected way. You may develop diabetes, thyroid disease, growth disorders, sexual dysfunction, and a host of other hormone-related disorders.
Glands of the Endocrine System
Each gland of the endocrine system releases specific hormones into your bloodstream. These hormones travel through your blood to other cells and help control or coordinate many body processes.
Endocrine glands include:
- Adrenal glands: Two glands that sit on top of the kidneys that release the hormone cortisol.
- Hypothalamus: A part of the lower middle brain that tells the pituitary gland when to release hormones.
- Islet cells in the pancreas: Cells in the pancreas that control the release of the hormones insulin and glucagon.
- Ovaries: The female reproductive organs that release eggs and produce sex hormones.
- Parathyroid: Four tiny glands in the neck that play a role in bone development.
- Pineal gland: A gland located near the center of the brain that may be linked to sleep patterns.
- Pituitary gland: It's present at the base of the brain behind the sinuses. It is often called the "master gland" because it influences many other glands, especially the thyroid. Problems with the pituitary gland can affect bone growth, a woman's menstrual cycles, and the release of breast milk.
- Testes: The male reproductive glands that produce sperm and sex hormones.
- Thymus: A gland in the upper chest that helps develop the body's immune system early in life.
- Thyroid: A butterfly-shaped gland in the front of the neck that controls metabolism.
Even the slightest hiccup with the function of one or more of these glands can throw off the delicate balance of hormones in your body and lead to an endocrine disorder, or endocrine disease.
Endocrine Disorder Causes
Endocrine disorders are typically grouped into two categories:
- Endocrine diseases that result when a gland produces too much or too little of an endocrine hormone, called a hormone imbalance.
- Endocrine diseases that happen due to the development of lesions (such as nodules or tumors) in the endocrine system, which may or may not affect hormone levels.
The endocrine feedback system helps control the balance of hormones in the bloodstream. If your body has too much or too little of a certain hormone, the feedback system signals the proper gland or glands to correct the problem. A hormone imbalance may occur if this feedback system has trouble keeping the right level of hormones in the bloodstream, or if your body doesn't clear them out of the bloodstream properly.
Increased or decreased levels of endocrine hormone may be caused by:
- A problem with the endocrine feedback system
- Disease
- Failure of a gland to stimulate another gland to release hormones (for example, a problem with the hypothalamus can disrupt hormone production in the pituitary gland)
- A genetic disorder, such as multiple endocrine neoplasia (MEN) or congenital hypothyroidism
- Infection
- Injury to an endocrine gland
- Tumor of an endocrine gland
Most endocrine tumors and nodules (lumps) are noncancerous. They usually don't spread to other parts of the body. However, a tumor or nodule on the gland may interfere with the gland's hormone production.
Symptoms of Endocrine Disorders
The symptoms of an endocrine disorder vary widely and depend on the specific gland involved. However, most people with endocrine disease complain of fatigue and weakness. Certain symptoms may make you think you have a different disease or disorder. Some symptoms that are worth talking to your doctor about include:
- Changes in your heart rate
- Changes to your skin or eyes
- Bone fractures
- High blood sugar levels
- High calcium levels
- Low or high blood pressure
- Unexplained changes in your weight
- Loss of sex drive
- Infertility
- Menstrual cycle disorders
Types of Endocrine Disorders
There are many different types of endocrine disorders. Diabetes is the most common endocrine disorder diagnosed in the U.S.
Other endocrine disorders include:
Adrenal insufficiency. The adrenal gland releases too little of the hormone cortisol and sometimes, aldosterone. Symptoms include fatigue, stomach upset, dehydration, and skin changes. Addison's disease is a type of adrenal insufficiency.
Cushing's disease. The overproduction of a pituitary gland hormone leads to an overactive adrenal gland. A similar condition called Cushing's syndrome may occur in people, particularly children, who take high doses of corticosteroid medications.
Gigantism (acromegaly) and other growth hormone problems. If the pituitary gland produces too much growth hormone, a child's bones and body parts may grow abnormally fast. If growth hormone levels are too low, a child can stop growing in height.
Hyperthyroidism. The thyroid gland produces too much thyroid hormone, leading to weight loss, fast heart rate, sweating, and nervousness. The most common cause for an overactive thyroid is an autoimmune disorder called Grave's disease.
Hypothyroidism. The thyroid gland does not produce enough thyroid hormone, leading to fatigue, constipation, dry skin, and depression. The underactive gland can cause slowed development in children. Some types of hypothyroidism are present at birth.
Hypopituitarism. In this condition, the pituitary gland releases little or no hormones. It may be caused by several different diseases. Women with this condition may stop getting their periods.
Multiple endocrine neoplasia type 1 and 2 (MEN1 and MEN2). These rare, genetic conditions are passed down through families. They cause tumors of the parathyroid, adrenal, and thyroid glands, leading to overproduction of hormones.
Polycystic ovary syndrome (PCOS). The overproduction of androgens interferes with the development of eggs and their release from the female ovaries. PCOS is a leading cause of infertility.
Precocious puberty. This refers to abnormally early puberty that occurs when glands tell the body to release sex hormones too soon in life.
Testing for Endocrine Disorders
If you have an endocrine disorder, your doctor may refer you to a specialist called an endocrinologist. An endocrinologist is specially trained in problems with the endocrine system.
Blood and urine tests to check your hormone levels can help your doctors determine if you have an endocrine disorder. Imaging tests may be done to help locate or pinpoint a nodule or tumor.
Treatment of endocrine disorders can be complicated, as a change in one hormone level can throw off another. Your doctor or specialist may order routine blood work to check for problems or to determine if your medication or treatment plan needs to be adjusted.
Takeaways
Your endocrine system releases hormones that affect how your body develops and functions. An endocrine system malfunction, caused by genetics, infection, or other factors, can result in various disorders such as diabetes, hyperthyroidism, and polycystic ovarian syndrome (PCOS). If you have fatigue or weakness regularly, it could be a sign of an endocrine disorder, so consult your doctor so that they can diagnose and treat your condition.
Endocrine Disorder FAQs
What are the four major endocrine conditions?
There aren't just four endocrine disorders. Some of the most common are:
- Diabetes
- Adrenal insufficiency
- Hyperthyroidism and Hypothyroidism
- Cushing's disease
- Gigantism (acromegaly) and other growth hormone problems.
- Hypopituitarism
- Multiple endocrine neoplasia type 1 and 2 (MEN1 and MEN2)
- Polycystic ovary syndrome (PCOS)
- Precocious puberty
What is the most common endocrine disorder?
In the U.S., diabetes is the most common endocrine disorder.
What are the symptoms of endocrine system disorders?
Endocrine disorders have various symptoms, but the most common are fatigue and weakness. Other symptoms include:
- Changes in your heart rate
- Changes to your skin or eyes
- Bone fractures
- High blood sugar levels
- High calcium levels
- Low or high blood pressure
- Unexplained changes in your weight
- Loss of sex drive
- Infertility
- Menstrual cycle disorders
What are the disorders caused by hormonal imbalance?
A hormonal imbalance (too much or too little of a hormone) can result in different types of endocrine disorders. Some examples include:
- Adrenal insufficiency, where the adrenal gland releases too little of the hormone cortisol and sometimes, aldosterone. Symptoms include fatigue, stomach upset, dehydration, and skin changes. Addison's disease is a type of adrenal insufficiency.
- Hyperthyroidism, where the thyroid gland produces too much thyroid hormone, which leads to weight loss, a fast heart rate, sweating, and nervousness. The most common cause for an overactive thyroid is an autoimmune disorder called Grave's disease.
- Polycystic ovary syndrome (PCOS), where an overproduction of androgens interferes with the development of eggs and their release from the female ovaries. PCOS is a leading cause of infertility.
