It means that in some patients the abnormal amyloid proteins deposit themselves in the kidneys thus damaging them. In this situation, the patient now has kidney disease in addition to the amyloidosis. Mild kidney disease is often called renal insufficiency.
Kidney disease is present when the kidneys partly or completely (kidney failure) lose their ability to carry out normal functions. It causes problems such as anemia, high blood pressure, and bone disease in the body by impairing hormone production by the kidneys.
The main function of the kidneys is to remove waste products and excess water from the blood. The kidneys process about 200 quarts of blood every day and produce about 2 quarts of urine. The waste products are generated from normal metabolic processes including the breakdown of active tissues, ingested foods, and other substances. Your kidneys allow you to continue to consume a variety of foods, drugs, vitamins and supplements, additives, and excess fluids without worry that toxic by-products will build up to harmful levels. The kidney also plays a major role in regulating levels of various minerals such as calcium, sodium, and potassium in the blood. Kidney disease is dangerous because water, waste, and toxic substances build up that normally are removed from the body by the kidneys. The most common finding is excess protein in the urine.