Amyloidosis is a group of diseases in which abnormal protein, known as amyloid fibrils, builds up in tissue. Symptoms include diarrhea, weight loss, feeling tired, enlargement of the tongue, bleeding, numbness, feeling faint with standing, swelling of the legs, or enlargement of the spleen.
There are different types of amyloidosis, each due to a specific protein misfolding. Some are genetic while others are acquired. The four most common types of systemic disease are light chain (AL), inflammation (AA), dialysis (Aβ2M), and hereditary and old age (ATTR).
Diagnosis may be suspected when protein is found in the urine, organ enlargement is present, or problems are found with multiple peripheral nerves are unknown. Diagnosis is confirmed by tissue biopsy.