What Is Multiple Myeloma?

Multiple myeloma is a type of blood cancer. It starts in your bone marrow, the spongy tissue inside bones. This is where your body makes blood cells, including a certain type called plasma cells. These cells can grow out of control and crowd out the normal, healthy ones in your bone marrow. When they build up, they form a tumor. The name “multiple myeloma” means there is more than one tumor.

Scientists aren’t sure what causes multiple myeloma. It might be linked to changes in DNA. But they do know that some people have a higher chance of getting the disease than others. Things that make your risk go up include:

  • Age. Most people with multiple myeloma are 45 or older. More than half are 65 or older.
  • Race. The disease is nearly twice as common in African-Americans.
  • Being male. It’s slightly more common in men.
  • Being overweight.
  • Hereditary. Other people in your family have had multiple myeloma.
  • You’ve had another plasma cell disease.



In the early stages of multiple myeloma, you might not have any symptoms, or they might be very mild. Everyone who has the disease will feel different effects. In general, it can cause:

  • Pain in your bones, especially in your back, ribs, and skull
  • Weakness
  • Fatigue
  • Feeling very thirsty
  • Getting infections and fevers often
  • Changes in how often you need to pee
  • Restlessness
  • Confusion
  • Nausea and vomiting
  • Loss of appetite
  • Weight loss
  • Numbness, especially in your legs

Multiple myeloma can affect your body in different ways.

Bones. The disease can make your bones weak and easy to break.

Blood. Because your bone marrow makes blood, multiple myeloma can affect how many healthy blood cells you have.

  • Too few red blood cells (called anemia) can make you feel weak, short of breath, or dizzy.
  • Too few white blood cells (called leukopenia) can make it easy to get infections like pneumonia. It can take longer to recover from them, too.
  • Too few platelets (called thrombocytopenia) makes it harder for wounds to heal. Even minor cuts can bleed too much.


Multiple myeloma can lead to too much calcium in your blood. This can give you belly pain and make you:

  • Thirsty
  • Pee a lot
  • Dehydrated
  • Constipated
  • Not feel like eating
  • Weak
  • Sleepy
  • Confused
  • Go into a coma (if your problem is severe)

Kidneys. Multiple myeloma and high levels of calcium can hurt your kidneys and make it harder for them to filter your blood. Your body might not be able to get rid of extra salt, fluid, and waste. This can make you:

  • Weak
  • Short of breath
  • Itchy
  • Have swelling in your legs

Stages of Multiple Myeloma

When your doctor diagnoses multiple myeloma, she’ll try to give you an idea of how much the cancer has grown or spread in your body. This is called the stage of your disease.

Doctors can tell what stage the multiple myeloma is in by looking at X-rays of your bones and testing your blood, pee, and bone marrow.

Your stage might be:

Smoldering myeloma. This is very early in the disease, when there are no symptoms or problems. The blood and kidneys are normal, and there is no bone damage. People who have smoldering myeloma often do not need treatment right away.

Stage I. There aren’t that many myeloma cells in the body. Doctors can’t see any bone damage on X-rays, or the cancer has damaged only one area of bone. The amount of calcium in the blood is normal. Other blood tests may be only slightly off-balance.

Stage II. This is the middle ground between stage I and stage III. There are more myeloma cells in the body than in stage I.

Stage III. There are many myeloma cells, and the cancer has destroyed three or more areas of bone. Blood calcium is high, and other blood tests are abnormal.

WebMD Medical Reference Reviewed by Laura J. Martin, MD on March 22, 2017



The Multiple Myeloma Research Foundation: “Learn the Basics About Multiple Myeloma,” “Risk Factors for Multiple Myeloma,” “Multiple Myeloma Symptoms,” “Multiple Myeloma Tests.”

American Red Cross: “Plasma.”

Johns Hopkins Medicine: “Multiple Myeloma.”

The American Cancer Society: “Do We Know What Causes Multiple Myeloma?” “What Are the Risk Factors for Multiple Myeloma?” “Signs and Symptoms of Multiple Myeloma,” “Staging Multiple Myeloma,” “Diagnosing Multiple Myeloma from Test Results,” “How Is Multiple Myeloma Staged?”

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