Definition & Facts for Hemochromatosis
In this section:
- What is hemochromatosis?
- Are there different types of hemochromatosis?
- How common is hemochromatosis?
- Who is more likely to have hemochromatosis?
- What are the complications of hemochromatosis?
What is hemochromatosis?
Hemochromatosis is a disorder in which extra iron builds up in the body to harmful levels.
Your body needs iron to stay healthy, make red blood cells, build muscle and heart cells, and do the daily tasks that your body and internal organs need to do. However, too much iron is harmful.
The human body typically controls the amount of iron that is absorbed from the diet, increasing the amount when iron is needed and decreasing the amount when iron levels in the body are too high. In hemochromatosis, the body absorbs too much iron from the diet each day.
Without treatment, hemochromatosis can cause iron overload, a buildup of iron that can damage many parts of the body, including the liver, heart, pancreas, endocrine glands, and joints.
Are there different types of hemochromatosis?
Primary hemochromatosis, also called hereditary or inherited hemochromatosis, is caused by inherited mutations in genes that control how much iron is absorbed from the diet.
Secondary hemochromatosis, also called secondary iron overload or hemosiderosis, is caused by too much iron in the diet or too much iron from blood transfusions, such as transfusions that treat severe anemia.
Neonatal hemochromatosis is a very rare condition caused by injury to the liver of a fetus in the womb. This liver injury causes extra iron to build up in the liver and other organs.
How common is hemochromatosis?
The most common forms of hemochromatosis are due to mutations in a gene called HFE. The HFE mutation that most commonly causes hemochromatosis is called C282Y. Another HFE mutation that may lead to iron overload is called H63D. People with two copies of C282Y are most likely to have iron overload. People with one copy of H63D and one copy of C282Y may also have iron overload, but this is less common and usually less severe.
About 1 in 15 people of Northern European ancestry have at least one copy of the C282Y mutation in the HFE gene.1 This means that about 1 in 225 people in this population have two copies of the gene and are at risk of developing hemochromatosis.2 Primary hemochromatosis is much less common in people of Asian or African ancestry because the C282Y gene mutation is far less common in these populations.
Who is more likely to have hemochromatosis?
Caucasians are more likely than other groups to have hemochromatosis because the C282Y gene mutation is most common in this population.
Men and women are just as likely to have C282Y mutations, but men are more likely to develop iron overload and the symptoms and complications of hemochromatosis. In people with these mutations, it can take many decades for iron to build up to harmful levels. Symptoms do not typically develop before age 40.3 On average, women develop symptoms about 10 years later than men do, usually after menopause.4 The differences between men and women are due to menstruation, which leads to blood loss and reduces iron levels in women.
Among people with the C282Y mutations, lifestyle factors and health problems can also increase the risk of severe iron overload and symptoms and complications of hemochromatosis. These include
- other chronic liver diseases, particularly chronic hepatitis C
- heavy alcohol drinking, which the National Institute on Alcohol Abuse and Alcoholism defines as more than 14 drinks per week for men and more than 7 drinks per week for women
What are the complications of hemochromatosis?
Without treatment, hemochromatosis may lead to iron overload and complications in your liver and other parts of your body.
In cirrhosis, scar tissue replaces healthy liver tissue and prevents your liver from working normally. Scar tissue also partly blocks the flow of blood through the liver. As cirrhosis gets worse, the liver begins to fail.
Cirrhosis may eventually lead to liver failure, also called end-stage liver disease. With liver failure, your liver is badly damaged and stops working. People with liver failure may require a liver transplant.
Cirrhosis increases your chance of getting liver cancer. Your doctor may suggest blood tests and an ultrasound or another type of imaging test to check for liver cancer. Finding cancer at an early stage improves the chance of curing the cancer.
In addition to harming the liver, iron overload can damage other parts of the body, including the joints, pancreas, heart, and sex glands. This damage can lead to
- heart failure
- loss of interest in sex and erectile dysfunction, because iron damage lowers sex hormone levels
This content is provided as a service of the National Institute of Diabetes and Digestive and Kidney Diseases
(NIDDK), part of the National Institutes of Health. The NIDDK translates and disseminates research findings to increase knowledge and understanding about health and disease among patients, health professionals, and the public. Content produced by the NIDDK is carefully reviewed by NIDDK scientists and other experts.