As cardiac amyloidosis progresses, the amyloid deposition can affect the hearts ability to pump and fill blood as well as its ability to maintain normal rhythm, which leads to worsening heart function and decline in peoples quality of life. Nervous system
People with amyloidosis do not get central nervous system involvement but can develop sensory and autonomic neuropathies. Sensory neuropathy develops in a symmetrical pattern and progresses in a distal to proximal manner. Autonomic neuropathy can present as orthostatic hypotension but may manifest more gradually with nonspecific gastrointestinal symptoms like constipation, nausea, or early satiety.Neuropathic presentation can depend on the etiology of amyloidosis. People with amyloidosis may experience dysfunction in various organ systems depending on the location and extent of nervous system involvement. For example, peripheral neuropathy can cause erectile dysfunction, incontinence and constipation, pupillary dysfunction, and sensory loss depending on the distribution of amyloidosis along different peripheral nerves. Amyloidosis of the central nervous system can have more severe and systemic presentations that may include life-threatening arrhythmias, cardiac failure, malnutrition, infection, or death. Gastrointestinal and accessory organs
Accumulation of amyloid proteins in the gastrointestinal system may be caused by a wide range of amyloid disorders and have different presentations depending on the degree of organ involvement. Potential symptoms include weight loss, diarrhea, abdominal pain, heartburn (gastrointestinal reflux), and GI bleeding.
Many amyloidoses are inherited, due to mutations in the precursor protein.Other forms are due to different diseases causing overabundant or abnormal protein production – such as with overproduction of immunoglobulin light chains (termed AL amyloidosis), or with continuous overproduction of acute phase proteins in chronic inflammation (which can lead to AA amyloidosis).About 60 amyloid proteins have been identified so far. Of those, at least 36 have been associated with a human disease.All amyloid fibril proteins start with the letter "A" followed by the protein suffix (and any applicable specification). See below for a list of amyloid fibril proteins which have been found in humans:

Alternative
An older clinical method of classification refers to amyloidoses as systemic or localised:

Systemic amyloidoses affect more than one body organ or system. Examples are AL, AA and Aβ2m. Localised amyloidoses affect only one body organ or tissue type. Examples are Aβ, IAPP, Atrial natriuretic factor (in isolated atrial amyloidosis), and Calcitonin (in medullary carcinoma of the thyroid)Another classification is primary or secondary. Primary amyloidoses arise from a disease with disordered immune cell function, such as multiple myeloma or other immunocyte dyscrasias. Secondary (reactive) amyloidoses occur as a complication of some other chronic inflammatory or tissue-destroying disease. Examples are reactive systemic amyloidosis and secondary cutaneous amyloidosis.Additionally, based on the tissues in which it is deposited, it is divided into mesenchymal (organs derived from mesoderm) or parenchymal (organs derived from ectoderm or endoderm). Treatment
Treatment depends on the type of amyloidosis that is present.