What Causes Acromegaly? Understanding the Root of Excessive Growth Hormone in Adults

Acromegaly is a rare but serious hormonal disorder that primarily affects adults after their growth plates have closed. Unlike gigantism, which occurs in children before bone fusion, acromegaly develops when the body produces too much growth hormone (GH) during adulthood. This overproduction leads to abnormal physical changes, including enlarged hands and feet, facial distortion, and internal organ enlargement.

Primary Cause: Pituitary Tumors

The most common cause of acromegaly is a benign tumor in the pituitary gland, known as a pituitary adenoma. These non-cancerous growths develop in the anterior part of the pituitary and secrete excessive amounts of growth hormone. Over 95% of acromegaly cases are linked to such tumors, which gradually increase GH levels and stimulate the liver to produce insulin-like growth factor 1 (IGF-1), amplifying tissue growth throughout the body.

How Pituitary Adenomas Trigger Symptoms

As the tumor grows, it not only disrupts hormonal balance but may also press on surrounding brain structures, leading to headaches, vision problems, or even partial blindness. The elevated GH levels cause noticeable physical transformations—patients often develop a protruding jaw (prognathism), widely spaced teeth, thickened skin, and deepened voice due to vocal cord enlargement. These facial changes occur slowly, sometimes over years, making early diagnosis challenging.

Less Common Causes and Risk Factors

In rare instances, acromegaly can result from tumors outside the pituitary gland, such as those in the pancreas, lungs, or adrenal glands. These neoplasms may produce growth hormone-releasing hormone (GHRH), which in turn stimulates the pituitary to overproduce GH. While genetic factors are not typically involved, certain inherited syndromes like multiple endocrine neoplasia type 1 (MEN1) can increase susceptibility.

Treatment Options and Long-Term Outlook

Early detection is crucial for effective management. Treatment usually begins with surgical removal of the pituitary tumor, especially if it's accessible via transsphenoidal surgery. For patients who aren't surgical candidates, radiation therapy and medications such as somatostatin analogs or GH receptor antagonists offer alternative control methods. With proper treatment, many symptoms can be reversed or stabilized, significantly improving quality of life.

Left untreated, acromegaly increases the risk of diabetes, hypertension, cardiovascular disease, and colon polyps. Therefore, ongoing monitoring and multidisciplinary care involving endocrinologists, neurosurgeons, and radiologists are essential for long-term success. Awareness of subtle physical changes can lead to earlier diagnosis and better outcomes.