Abnormal bone growth: in children, the chemical changes of acromegaly result in exceptional growth of long bones, causing unusual height; acromegaly occurring after long bone growth stops, as in adults, can result in enlarged hands and feet, widened fingers or toes, enlarged jaw or tongue, and enlarged facial bones.

Anesthesia: loss of the ability to feel pain, caused by administration of a drug or by other medical interventions.

Aortic valve: one of the four valves in the heart, this valve is situated at exit of the left lower chamber of the heart where the aorta (the largest of all arteries) begins.

Benign tumor: a noncancerous growth that does not invade nearby tissue or spread to other parts of the body.

Cardiologist: a physician skilled in the prevention, diagnosis, and treatment of heart disease.

Carpal tunnel syndrome: compression of the median nerve at the wrist, which may result in numbness, tingling, weakness, or muscle damage in the hand and fingers.

Computed tomography (CT) scan: an imaging method that uses x-rays to create cross-sectional pictures of the body.

Echocardiogram: a test that uses sound waves to create a moving picture of the heart; much more detailed than x-ray image and involves no radiation exposure.

Endocrinologist: a specialist in endocrinology, the study of hormones, the endocrine system, and their role in the physiology of the body.

Gallbladder: a pear-shaped organ just below the liver that stores the bile secreted by the liver; during a fatty meal, the gallbladder contracts, delivering the bile through the bile ducts into the intestines to help with digestion.

Goiter: an enlargement of the thyroid gland, causing a swelling in the front part of the neck.

Growth factor: a substance made by the body that functions to regulate cell division and cell survival.

Growth hormone: a hormone made in the pituitary gland that stimulates the release of another hormone by the liver, thereby causing growth.

Insulin-like growth factor-1 (IGF-1): a hormone similar in structure to insulin; it plays an important role in childhood growth and continues to have effects in adults.

Intramuscular: an injection directly into the substance of a muscle.

Magnetic resonance image (MRI): a special technique designed to image internal structures of the body using magnetism, radio waves, and a computer to produce the images of body structures.

Microsurgery: surgery through a microscope; microsurgery is used to operate on very small structures, such as glands, and often requires miniaturized instruments.

Migraine: an often hereditary condition with periodic attacks of headache, irritability, nausea, vomiting, constipation or diarrhea, and often sensitivity to light.

Mitral valve: a valve in the heart between the left upper chamber and the left lower chamber that permits blood to flow from the upper into the lower chamber, but not in the reverse direction.

Needle-phobic: afraid of needles and injections.

Neurologist: a physician who focuses on the nervous system and the brain.

Ophthalmologist: a physician who specializes in the diagnosis, and medical and surgical treatment of diseases and defects of the eye and related structures.

Oral glucose tolerance test (OGTT): a laboratory test to check how the body breaks down blood sugar.

Pituitary gland: the main endocrine gland; it is a small structure in the head and is called the master gland because it produces hormones that control other glands and many body functions including growth.

Quadrant: any one of four quarters, as of the buttocks; the upper left or right, the lower left or right.

Rheumatologist: a specialist in disorders marked by inflammation, degeneration, or metabolic derangement of connective tissue structures of the body, especially the joints and related structures, including muscles, sacs, tendons, and fibrous tissue, with pain, stiffness, or limitation of motion.

Sebaceous gland: a normal gland of the skin which empties an oily secretion into the hair follicle near the surface of the skin.

Somatostatin: a hormone in the pancreas that helps tell the body when to make other hormones.

Somatostatin analog: a chemical compound with a structure similar to that of somatostatin but differing in some respects; it serves a function similar to somatostatin in the body.