Multiple myeloma typically develops slowly. It may exist for years undiagnosed because it causes so few symptoms. When it does cause symptoms, they are usually related to buildup of abnormal protein in the blood or to the destruction of bone by the growing tumor.

If you experience any of these symptoms do not assume it is due to cancer. Most of these symptoms may be caused by other, less serious health conditions. If you experience any one of them, see your doctor.

Symptoms of multiple myeloma include the following:

Fatigue—This occurs when there are not enough red blood cells to carry oxygen to the tissues. It is a sign of ]]>anemia]]> and is a result of myeloma cells interfering with the normal growth of red cells in the bone marrow.

Kidney failure—High levels of an abnormal protein in the blood cause this symptom.

Bone pain—This is most often in the back, but also in the limbs or ribs because of bone loss or fracture as a result of the build up of myeloma cells.

Broken bones—This is due to weakening of bone tissue or pressure from the myeloma cells growing in a single mass (tumor).

Repeated infections—This may be due to abnormal antibody production by myeloma cells or because there are too few active, normal cells (including white blood cells) in the immune system to respond to infection.

Abnormal bleeding—This results from too few platelets, which are essential for blood clotting.

Mental changes, confusion—This is due to the blood becoming too thick or changes in its composition, such as too much calcium as a result of bone loss.

Weight loss—An unintentional loss of weight is a common symptom of cancer.