Amyloidosis is a group of rare diseases. It involves deposits of a protein called amyloid. These proteins build up in body tissues and organs. There are three major forms:

  • Primary amyloidosis—found in the heart, lungs, skin, tongue, thyroid gland, intestines, liver, kidneys, and blood vessels
  • Secondary amyloidosis—found in the spleen, liver, kidneys, adrenal glands, and lymph nodes
  • Hereditary amyloidosis—found in the nerves, heart, blood vessels, and kidneys

The causes of amyloidosis vary in its different forms:

  • Primary amyloidosis—caused by the deposit of antibody fragments; associated with bone marrow disorders such as multiple myeloma
  • Secondary amyloidosis—develops in response to chronic infection or inflammatory disease
  • Hereditary amyloidosis—caused by mutations of amyloid in the blood