Endocrinology is the study of glands and parts of glands that produce hormones. These hormones control many basic bodily functions. The metabolism of food, the sex and reproductive systems, how blood sugar levels are maintained, blood pressure, the balance of salt in the body, body heat, energy levels and bone growth all depend on the endocrine system.
Problems within the endocrine system can result in numerous disorders, including diabetes, obesity, thyroid disorders, osteoporosis and hormone malfunction. Symptoms of endocrine disorders often take months or years to show up and can be easily overlooked by the patient.
Many patients also suffer from other serious conditions, such as heart disease, stroke, high blood pressure and circulatory problems. These often call for exacting and sophisticated medical techniques and careful monitoring by specialists from different fields.
Overview of the Endocrine System
The body’s seven endocrine glands are the pituitary gland, thyroid gland, parathyroid glands, adrenal glands, islets of langerhans, ovaries and testes.
Pituitary Gland
This is a pea-sized, reddish-gray organ in the center of the brain, just above the back of the nose. It regulates various hormones that directly or indirectly affect most basic bodily functions. Disorders of the pituitary gland include Cushing’s disease (which causes fat to build up in the face, back and chest) and acromegaly (in which the hands, feet and face are larger than normal).
Thyroid Gland
The thyroid gland is a butterfly-shaped gland just above the collarbone. The hormones it produces regulate your metabolism (how your body burns calories to produce energy) and influence heart rate, digestion, muscle strength, cholesterol levels and even your frame of mind.
Hyperthyroidism is a condition in which too much thyroid is produced. The most common cause of hyperthyroidism is Graves’ disease (also known in Europe as von Basedow’s disease), but other causes include growths in the thyroid gland and thyroiditis (inflammation of the thyroid gland). Untreated hyperthyroidism can lead to atrial fibrillation, osteoporosis and a life-threatening condition called thyroid storm. Regular medical checkups are important if you have had hyperthyroidism because it can develop again. You may also be at increased risk for other problems, such as hypothyroidism and an eye condition called Graves’ ophthalmopathy.
Having too little thyroid hormone is most often the result of the body’s own natural defense (immune) system attacking the thyroid gland. This condition is called autoimmune thyroiditis or Hashimoto’s thyroiditis. Surgery to remove the thyroid or radiation treatment of the thyroid may also cause hypothyroidism. Untreated hypothyroidism can cause fatigue, lethargy, depression, memory problems, constipation, dry skin, intolerance to cold and other symptoms. In newborns, untreated hypothyroidism can lead to mental retardation. While still in the hospital, all newborns are checked for hypothyroidism.
Hypothyroidism is treated with medications to replace the thyroid hormone. Symptoms usually disappear within a few months after treatment begins, but most people need to continue taking thyroid hormones for life.
Parathyroid Glands
These are four small glands that are beside or embedded in the thyroid gland. The hormone that they secrete regulates the metabolism of calcium and phosphorus in the body.
Hypoparathyroidism is a condition in which too little parathyroid hormone is present in the body. This can cause an abnormally low level of calcium in the blood. Symptoms include weakness, muscle cramps, nervousness headaches or tetany, an uncontrollable twitching and crampy spasms of the hands, feet, arms and/or face.
Adrenal Glands
These are a pair of organs above each kidney. These glands produce several hormones, including adrenaline (also known as epinephrine), which is the main blood-pressure raising hormone, and norepinephrine, which is the chemical means by which messages are transmitted across the synapses of the nerves. High blood pressure is one consequence of adrenal gland disorders.
Islets of Langerhans
These are groups of small, slightly granular cells around the pancreas that secrete insulin, which is important for regulating the amount of sugar in the blood and glucagon. Diabetes is the main consequence of disorders in this endocrine gland.
Ovaries
These are a pair of organs (about an inch-and-a-half long) in women that produce eggs and female sex hormones. Disorders of these glands include Turner syndrome (in which women are short and fail to develop sexually at puberty), disruptions of normal sexual development and infertility.
Testes
These are a pair of organs in men that produce sperm and male sex hormones, such as testosterone. Conditions caused by a disorder of these glands include abnormal sexual development and fertility problems.