Adult Growth Hormone Deficiency
Sometimes adults’ bodies don’t produce enough growth hormone.
Growth hormone is a special type of protein made in the brain by the pituitary gland, and it is responsible for more than just physical growth—it helps our muscles, bones, even our metabolism. While growth hormone deficiency in children can result in lack of growth, adults can also suffer from a lack of growth hormone that affects their bodies in other ways.
Growth hormone deficiency can occur at any age, when the pituitary gland doesn’t produce enough growth hormone. If your doctor has given you or someone you care for a diagnosis of adult growth hormone deficiency, it may help you to know that this medical condition is treatable.
Causes of Adult GHD.
About 50,000 adults in the United States have growth hormone deficiency, with about 6,000 new patients diagnosed every year. There are two main causes:
- A person may have been born with growth hormone deficiency. Most of these individuals are diagnosed as children. A number of the more severe cases will need treatment throughout life. However, some children may not be diagnosed and end up finding out they have growth hormone deficiency as adults.
- An adult may become growth hormone deficient due to damage to the pituitary or hypothalamus gland. The damage may be caused by tumors of these glands, surgery or radiation treatment to remove these tumors, or even a severe head injury.
In 90% of adults, growth hormone deficiency is a result of benign (non-cancerous) tumors called pituitary adenomas, commonly diagnosed in patients in their 30s or 40s. Rare causes of adult GHD include diseases such as sarcoidosis, tuberculosis, histiocytosis and hemochromatosis (iron overload).
Diagnosing growth hormone deficiency in adulthood.
Most children with growth hormone deficiency have obvious symptoms, such as short stature. But because adults have already reached their full height, the symptoms of adult growth hormone deficiency are different. Growth hormone plays a role in bone development, muscle development, and fat and weight gain.
Some symptoms of adult growth hormone deficiency can be caused by other conditions. If you have a history of childhood growth hormone deficiency, you might want to talk to your doctor.
If your doctor suspects the possibility of adult GHD, he or she may refer you to an endocrinologist, a doctor who specializes in hormone disorders.
In order for the endocrinologist to confirm you have adult GHD, they may order a stimulation test or "stim" test. During this test, a patient is given a medication that causes the pituitary gland to release large amounts of growth hormone at once. Several blood samples are taken over a period of time, measuring the amount of growth hormone in the body. Your endocrinologist may need to do more than one stim test to accurately diagnose growth hormone deficiency.
You should also ask your health care professional about adult growth hormone deficiency if you have a history of pituitary damage and are just noticing some of these signs and symptoms: