Acromegaly
Excess growth hormone causing gradual body changes in adults
Quick Facts
- Type: Hormone (endocrine) disorder
- Hormone involved: Growth hormone
- Usual cause: Benign pituitary tumor
- Key feature: Slow enlargement of hands, feet, face
Overview
Acromegaly is a hormone disorder that develops when the body produces too much growth hormone in adulthood. Growth hormone is made by the pituitary gland, a small gland at the base of the brain. In acromegaly, excess growth hormone causes bones and tissues to enlarge gradually, most noticeably in the hands, feet, and face.
The changes happen slowly over years, so the condition is often not recognized until well after it begins. The most common cause is a benign (noncancerous) tumor of the pituitary gland. Untreated, acromegaly can lead to serious health problems, but treatment can control hormone levels and improve symptoms and long-term health.
Symptoms
Symptoms develop gradually and can be easy to miss at first. They include:
- Enlarged hands and feet, with rings or shoes no longer fitting
- Changes in facial features, such as a more prominent jaw and brow and coarser features
- Wider spacing of the teeth
- Thickened, oily skin and excessive sweating
- Joint pain
- Headaches and, if a tumor presses on nearby nerves, vision problems
- Deepening of the voice
- Fatigue, and in some people, sleep apnea or tingling in the hands (carpal tunnel syndrome)
If too much growth hormone occurs before adulthood, before the growth plates close, it causes excessive height, a related condition called gigantism.
Causes
Acromegaly is caused by excess growth hormone, which in turn raises levels of another growth-promoting hormone (IGF-1). The main causes are:
- Pituitary tumor: In the large majority of cases, a benign tumor (adenoma) of the pituitary gland produces too much growth hormone. The tumor can also press on nearby structures, causing headaches or vision changes.
- Non-pituitary tumors: Rarely, tumors elsewhere in the body produce growth hormone or a hormone that stimulates its release.
Risk Factors
- Presence of a pituitary tumor
- Rare inherited conditions or genetic syndromes that increase the risk of pituitary tumors
- A family history of such syndromes
Most cases occur without a clear inherited cause and are diagnosed in middle adulthood.
Diagnosis
Because changes are gradual, diagnosis is often delayed. When acromegaly is suspected, blood tests measure IGF-1, which is usually elevated. An oral glucose tolerance test, which checks whether growth hormone is suppressed after drinking a sugary solution, helps confirm the diagnosis (it is not suppressed in acromegaly).
If tests confirm excess growth hormone, an MRI of the pituitary gland is used to find a tumor and assess its size. Additional tests may check vision and other pituitary hormones, and screen for complications such as diabetes, heart disease, or sleep apnea.
Treatment
The goals of treatment are to lower growth hormone levels, relieve symptoms, control any tumor, and prevent complications. Options include:
- Surgery: Removing the pituitary tumor, often through the nose (transsphenoidal surgery), is frequently the first treatment and can cure or greatly improve the condition.
- Medications: Drugs that lower growth hormone production or block its effects, used when surgery is not fully effective or not possible.
- Radiation therapy: Used in some cases to shrink remaining tumor tissue and lower hormone levels over time.
People also receive care for related problems such as diabetes, high blood pressure, joint disease, and sleep apnea, and need ongoing monitoring.
When to See a Doctor
See a doctor if you notice gradual enlargement of your hands or feet, changes in your facial features, new gaps between your teeth, persistent joint pain, or rings and shoes that no longer fit. Because changes are slow, comparing old photographs can help reveal them.
Seek prompt medical care for sudden, severe headache, sudden vision loss or double vision, or symptoms such as confusion, which can rarely signal a serious problem with a pituitary tumor. These need urgent evaluation.
Frequently Asked Questions
What causes acromegaly?
In most cases, a benign (noncancerous) tumor of the pituitary gland produces too much growth hormone. Rarely, tumors elsewhere in the body cause it. The excess growth hormone leads to the gradual enlargement of the hands, feet, and facial features.
How is acromegaly different from gigantism?
Both involve excess growth hormone. Acromegaly occurs in adulthood after the bones' growth plates have closed, so bones thicken and features enlarge. Gigantism occurs in childhood before the growth plates close, causing excessive height.
Why is acromegaly often diagnosed late?
The body changes develop very slowly over years, so they are easy to overlook. Comparing current and older photographs can help reveal the gradual changes, and blood tests for IGF-1 confirm the diagnosis.
Can acromegaly be treated?
Yes. Surgery to remove the pituitary tumor is often the first treatment and can cure or greatly improve the condition. Medications and radiation therapy are used when needed, along with care for related problems such as diabetes and sleep apnea.
What complications can acromegaly cause?
Untreated, it can lead to high blood pressure, type 2 diabetes, heart disease, joint problems, sleep apnea, and vision problems if a pituitary tumor presses on nearby nerves. Treatment lowers these risks, which is why early diagnosis matters.
References
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Acromegaly.
- Mayo Clinic. Acromegaly — Symptoms and causes.
- The Endocrine Society.
- MedlinePlus, U.S. National Library of Medicine. Acromegaly.