What are gigantism and acromegaly?
Gigantism and acromegaly are patterns of abnormal growth caused by having too much growth hormone.
In children, too much growth hormone causes gigantism, meaning being gigantic or a giant.
In adults, too much growth hormone causes acromegaly.
In gigantism, children grow to be very tall
In acromegaly, adults don't grow taller (because the growth plates in their bones are closed), but they have deformed bones and skull
Other symptoms include weakness, vision problems, and heart problems that can lead to heart failure Heart Failure Your heart pumps blood to carry oxygen and nutrients to the rest of your body. Heart failure is when your heart doesn’t pump blood as well as it should. It doesn’t mean your heart has stopped... read more
Doctors treat gigantism and acromegaly with surgery and medicines to lower growth hormone levels
What causes gigantism and acromegaly?
Gigantism and acromegaly are almost always caused by:
A noncancerous (benign) tumor on your pituitary gland that makes extra growth hormone

The pituitary gland Overview of the Pituitary Gland The pituitary gland is a pea-sized bit of tissue at the bottom of your brain. Glands are organs that make and release hormones into your blood. Hormones are chemicals that stimulate other cells... read more is a pea-sized bit of tissue at the bottom of your brain. Glands are organs that make and release hormones into your blood. Hormones are chemicals that stimulate other cells or tissues into action. Your pituitary gland Overview of the Pituitary Gland The pituitary gland is a pea-sized bit of tissue at the bottom of your brain. Glands are organs that make and release hormones into your blood. Hormones are chemicals that stimulate other cells... read more makes many different types of hormones, including growth hormone.
The extra growth hormone in your blood causes your bones, muscles, and organs to grow bigger.
Locating the Pituitary Gland
![]() |
What are the symptoms of gigantism?
Gigantism is a disease of children. Symptoms include:
Extreme growth of long bones, so arms and legs are very long
Growing very tall
Starting puberty later than normal
Sometimes, problems with the development of the genitals
What are the symptoms of acromegaly?
Acromegaly is a disease that usually starts between the ages of 30 and 50. Unlike children's bones, adult's bones can't grow longer. Instead, their bones change shape and deform. Symptoms include:
Coarsening, thickened facial features
Swollen hands and feet
Needing to get larger-sized rings, gloves, hats, and shoes
A thick, barrel-shaped ribcage
Joint pain
Sometimes, weakness in arms and legs
In women, irregular periods
In men, erectile dysfunction
What problems do gigantism and acromegaly cause?
Untreated gigantism and acromegaly can cause:
Increased chance of diabetes Diabetes Diabetes is a disease in which your blood sugar (glucose) levels are too high. You get diabetes if your body's normal way of controlling blood sugar isn't working right. There are 2 types of... read more , high blood pressure High Blood Pressure Each heart beat pushes blood through your arteries. Arteries are the blood vessels that carry blood from your heart to your body. Blood pressure is the pressure of blood in your arteries. Without... read more , and sleep apnea Sleep Apnea Sleep apnea is when your breathing slows or stops for a short time while you're sleeping and then restarts. If you have sleep apnea, this happens over and over each time you sleep, often many... read more
People with untreated gigantism and acromegaly have a shorter life expectancy.
How can doctors tell if a person has gigantism or acromegaly?
It's usually easy to see when children are growing too much. But in adults, it may take a long time to notice the abnormal bone growth in acromegaly because it happens little by little.
If doctors suspect gigantism or acromegaly, they:
Sometimes, look at photos of you taken over time—these can show physical changes common in acromegaly
Do blood tests to measure growth hormone levels
Do x-rays Plain X-Rays A plain x-ray is an imaging test that takes a picture of the inside of your body. It uses a low dose of x-ray radiation. X-rays show body parts according to how dense (solid) they are. Doctors... read more
of your hands to look for thickened bones or swollen tissue
Do CT scan Computed Tomography A CT scan uses a large machine shaped like a large donut to take x-rays from many angles. A computer then takes the x-rays and creates many detailed pictures of the inside of your body. Each... read more (computed tomography) or MRI Magnetic Resonance Imaging (MRI) MRI is a test that uses a machine with a powerful magnet to make pictures of the inside of your body. A computer records changes in the magnetic field around your body. The computer then uses... read more
(magnetic resonance imaging) of the brain to look for a tumor in your pituitary gland
How do doctors treat gigantism and acromegaly?
Doctors treat gigantism and acromegaly using a combination of:
Surgery to remove a pituitary gland tumor
Radiation therapy
Medicine that stops you from producing growth hormone
After surgery or radiation to treat a pituitary gland tumor, you may need to take hormone supplements to replace the ones the pituitary makes.