Amyloidosis (am-uh-loi-DO-sis) is a rare disease that occurs when a substance called amyloid builds up in your organs. Amyloid is an abnormal protein that is produced in your bone marrow and can be deposited in any tissue or organ.
Amyloidosis can affect different organs in different people, and there are different types of amyloid. Amyloidosis frequently affects the heart, kidneys, liver, spleen, nervous system and digestive tract. Severe amyloidosis can lead to life-threatening organ failure.
There's no cure for amyloidosis. But treatments can help you manage your symptoms and limit the production of amyloid protein.
Amyloidosis care at Mayo Clinic
You may not experience signs and symptoms of amyloidosis until the condition is advanced. When signs and symptoms are evident, they depend on which of your organs are affected.
Signs and symptoms of amyloidosis may include:
- Swelling of your ankles and legs
- Severe fatigue and weakness
- Shortness of breath
- Numbness, tingling or pain in your hands or feet, especially pain in your wrist (carpal tunnel syndrome)
- Diarrhea, possibly with blood, or constipation
- Unintentional, significant weight loss
- An enlarged tongue
- Skin changes, such as thickening or easy bruising, and purplish patches around the eyes
- An irregular heartbeat
- Difficulty swallowing
When to see a doctor
See your doctor if you persistently experience any of the signs or symptoms associated with amyloidosis.
In general, amyloidosis is caused by the buildup of an abnormal protein called amyloid. Amyloid is produced in your bone marrow and can be deposited in any tissue or organ. The specific cause of your condition depends on the type of amyloidosis you have.
There are several types of amyloidosis, including:
- AL amyloidosis (immunoglobulin light chain amyloidosis) is the most common type and can affect your heart, kidneys, skin, nerves and liver. Previously known as primary amyloidosis, AL amyloidosis occurs when your bone marrow produces abnormal antibodies that can't be broken down. The antibodies are deposited in your tissues as amyloid, interfering with normal function.
- AA amyloidosis mostly affects your kidneys but occasionally your digestive tract, liver or heart. It was previously known as secondary amyloidosis. It occurs along with chronic infectious or inflammatory diseases, such as rheumatoid arthritis or inflammatory bowel disease.
- Hereditary amyloidosis (familial amyloidosis) is an inherited disorder that often affects the liver, nerves, heart and kidneys. Many different types of gene abnormalities present at birth are associated with an increased risk of amyloid disease. The type and location of an amyloid gene abnormality can affect the risk of certain complications, the age at which symptoms first appear, and the way the disease progresses over time.
- Dialysis-related amyloidosis develops when proteins in blood are deposited in joints and tendons — causing pain, stiffness and fluid in the joints, as well as carpal tunnel syndrome. This type generally affects people on long-term dialysis.
Anyone can develop amyloidosis. Factors that increase your risk include:
- Age. Most people diagnosed with AL amyloidosis, the most common type, are between ages 60 and 70, although earlier onset occurs.
- Sex. Nearly 70 percent of people with AL amyloidosis are men.
- Other diseases. Having a chronic infectious or inflammatory disease increases your risk of AA amyloidosis.
- Family history. Some types of amyloidosis are hereditary.
- Kidney dialysis. Dialysis can't always remove large proteins from the blood. If you're on dialysis, abnormal proteins can build up in your blood and eventually be deposited in tissue. This condition is less common with modern dialysis techniques.
- Race. People of African descent appear to be at higher risk of carrying a genetic mutation associated with the type of amyloidosis that can harm the heart.
The potential complications of amyloidosis depend on which organs the amyloid deposits affect. Amyloidosis can seriously damage your:
- Kidneys. Amyloid can harm the kidneys' filtering system, causing protein to leak from your blood into your urine. The kidneys' ability to remove waste products from your body is lowered, which may eventually lead to kidney failure.
- Heart. Amyloid reduces your heart's ability to fill with blood between heartbeats. Less blood is pumped with each beat, and you may experience shortness of breath. If amyloidosis affects your heart's electrical system, your heart rhythm may be disturbed.
Nervous system. You may experience pain, numbness or tingling of the fingers or numbness, lack of feeling or a burning sensation in your toes or the soles of your feet. If amyloid affects the nerves that control your bowel function, you may experience periods of alternating constipation and diarrhea.
If the condition affects nerves that control blood pressure, you may experience dizziness or near fainting when standing too quickly.