Hormonal and Metabolic Disorders - MSD Manual Consumer Version

Biology of the Endocrine System

The endocrine system consists of a group of glands and organs that regulate and control various body functions by producing and secreting hormones. Hormones are chemical substances that affect the activity of another part of the body. In essence, hormones serve as messengers, controlling and coordinating activities throughout the body.
Acid-Base Balance

An important part of being healthy is for the blood to maintain a normal degree of acidity or alkalinity. The acidity or alkalinity of any solution, including blood, is indicated on the pH scale. The pH scale, ranges from 0 (strongly acidic) to 14 (strongly basic or alkaline). A pH of 7.0, in the middle of this scale, is neutral. Blood is normally slightly basic, with a normal pH range of about 7.35 to 7.45. Usually the body maintains the pH of blood close to 7.40.
Adrenal Gland Disorders

The body has two adrenal glands, one near the top of each kidney. They are endocrine glands, which secrete hormones into the bloodstream. Each adrenal gland has two parts.
Amyloidosis

Amyloidosis is a rare disease in which abnormally folded proteins form into collections called amyloid fibrils that accumulate in various tissues and organs, sometimes leading to organ dysfunction, organ failure, and death.
- Amyloidosis
Carcinoid Tumors

Carcinoid tumors are noncancerous (benign) or cancerous (malignant) growths that sometimes produce excessive amounts of hormone-like substances (such as serotonin), resulting in the carcinoid syndrome. Carcinoid syndrome is a group of specific symptoms that occur as a result of these hormones.
- Carcinoid Tumors and Carcinoid Syndrome
Cholesterol Disorders

The body needs fats (lipids) for growth and energy. It also uses them to synthesize hormones and other substances needed for the body’s activities. The body may deposit excess fat in blood vessels and within organs, where it can block blood flow and damage organs, often causing serious disorders.
Diabetes Mellitus (DM) and Disorders of Blood Sugar Metabolism

Diabetes mellitus is a disorder in which the body does not produce enough or respond normally to insulin, causing blood sugar (glucose) levels to be abnormally high.
Electrolyte Balance

More than half of a person's body weight is water. Doctors think about water in the body as being restricted to various spaces, called fluid compartments. The three main compartments are
Multiple Endocrine Neoplasia Syndromes

Multiple endocrine neoplasia syndromes are rare, inherited disorders in which several endocrine glands develop noncancerous (benign) or cancerous (malignant) tumors or grow excessively without forming tumors.
- Multiple Endocrine Neoplasia Syndromes (MEN)
  - Types
  - Diagnosis
  - Treatment
Parathyroid Disorders

(See also Overview of the Thyroid Gland; Hypercalcemia; and Hypocalcemia.)
Pituitary Gland Disorders

The pituitary is a pea-sized gland that is housed within a bony structure (sella turcica) at the base of the brain. The sella turcica protects the pituitary but allows very little room for expansion.
Polyglandular Deficiency Syndromes

Polyglandular deficiency syndromes are hereditary disorders in which several endocrine (hormone-producing) glands malfunction.
Porphyrias

Porphyrias are a group of disorders caused by deficiencies of enzymes involved in the production of heme.
Thyroid Gland Disorders

The thyroid is a small gland, measuring about 2 inches (5 centimeters) across, that lies just under the skin below the Adam’s apple in the neck. The two halves (lobes) of the gland are connected in the middle (called the isthmus), giving the thyroid gland the shape of a bow tie. Normally, the thyroid gland cannot be seen and can barely be felt. If it becomes enlarged, doctors can feel it easily, and a prominent bulge (goiter) may appear below or to the sides of the Adam’s apple.
Water Balance

Water accounts for about one half to two thirds of an average person’s weight. Fat tissue has a lower percentage of water than lean tissue and women tend to have more fat, so the percentage of body weight that is water in the average woman is lower (52 to 55%) than it is in the average man (60%). The percentage of body weight that is water is also lower in older people and in obese people. The percentage of body weight that is water is higher (70%) at birth and in early childhood.