R - Renal (kidney) problems: Poor kidney function is a classic sign of multiple myeloma. Other signs and symptoms of multiple myelomaBeyond the CRAB criteria, multiple myeloma can cause a range of other symptoms. Risk factors for multiple myelomaWhile the exact cause of multiple myeloma isn’t known, there are several risk factors that we do know about. Even fatigue, one of the most common myeloma symptoms, is usually attributed to depression, sleep disorders, thyroid problems, or other chronic conditions before multiple myeloma is considered. Blood tests measure the levels of red blood cells, white blood cells, and platelets — and a low red blood cell count may signal anemia.