Multiple myeloma develops slowly over the course of several years. The body is initially able to compensate for changes in blood so symptoms may not appear until it is in advanced stages. Symptoms depend on the blood cells affected and the location of the tumors. 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. However, it is still important to discuss them with your doctor. Early detection and treatment improve outcomes for both cancer and other health conditions.

Bone pain can appear anywhere, but is most common in the back, ribs, hips, or skull. Normally, healthy bone tissue is maintained through a constant process of breaking down old bone tissue and rebuilding new tissue. Myeloma cells can boost bone destruction without increasing the rebuilding process. As a result, the bone becomes weak and easily fractured. Even small fractures in the bone can cause pain.

Bone pain can also be caused by growth of tumors.

A drop in the number of normal white blood cells makes it harder for the body to fight infection. Symptoms may include:

  • Frequent infections like colds or sinus infections
  • Persistent fever that is not specific to another condition
  • Flu-like symptoms
  • Night sweats
  • Minor cuts that heal slowly—the area around the cut may become red and swollen

A drop in the number of normal red blood cells is called anemia, which decreases the amount of oxygen reaching the body's tissues. Symptoms of anemia may include:

  • Weakness and fatigue
  • Pale skin
  • Lightheadedness
  • Rapid heart beat
  • Shortness of breath
  • Headache
  • Mood changes

A drop in the number of normal platelet cells makes it harder for blood to clot properly. Without clotting, even small injuries can lead to severe bleeding. Symptoms may include:

  • Bleeding or bruising easily
  • Nosebleeds
  • Bleeding gums
  • Tiny red spots under the skin
  • Heavy menstruation

The accelerated breakdown of bone tissue caused by multiple myeloma releases excess levels of calcium into the blood. In most cases, elevated calcium levels in the blood may go undetected. As levels increase, serious symptoms may appear, which require treatment. High levels of calcium in the blood, called hypercalcemia, may cause:

  • Bone pain
  • Nausea or vomiting
  • Fatigue or weakness
  • Extreme thirst
  • Loss of appetite with or without unintended weight loss
  • Constipation
  • Kidney problems
  • Impaired mental function and confusion

Untreated or severe hypercalcemia can to kidney failure, coma, or death.

Depending on it's location, multiple myeloma tumors can cause:

  • Compression on spinal nerves, which can lead to:
  • Injury to the kidneys, which can lead to:
    • Collection of fluid in the legs or shortness of breath if the lungs are affected
    • Itchy skin
    • Fatigue
  • Abnormal levels of blood cells can lead to blood thickening, which can lead to:
  • Heart arrhythmias
  • Swollen tongue
  • Weakness in the wrist or hand—carpal tunnel syndrome
  • Diarrhea