How Multiple Myeloma Affects the Body

Medically Reviewed By William C. Lloyd III, MD, FACS
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More than 24,000 people are diagnosed each year in the United States with the bone marrow cancer known as multiple myeloma. Multiple myeloma is a cancer of the plasma cells that are found in the spongy bone marrow tissue at the heart of your bones. Essentially, the body begins to make abnormal plasma cells --lots of them--and they begin to take over. These malignant plasma cells clump together to create tumors. Among others, multiple myeloma affects the bones and reduce the body’s ability to fight off infection. But it can affect other bodily functions, too.

Your Immune System

Plasma cells, which are found mainly in the bone marrow, are part of the immune system. Normally, they produce antibodies to fight off infection. But when they become cancerous, they no longer function normally to fight off infections. They begin to proliferate, flood the circulation with excess antibodies, and eventually the overwhelming population of malignant plasma cells crowd out and kill off the normal blood cells. This makes it harder for your body to fight off foreign invaders that can make you sick.

Your Bones

As you might expect from a cancer that affects the tissue inside your bones, you’ll feel it in your bones. One of the most common first signs of multiple myeloma is bone pain that’s triggered by movement. This pain is usually located in the chest (ribs), hips or back, although it can develop in the bones of the arms or legs.

People with multiple myeloma can actually lose bone, too, as the cancer cells interfere with the action of the cells that build new bone and replace old bone. Unfortunately, this bone loss can lead to another problematic condition, osteoporosis. The bones become more fragile, and bone fractures often develop.

Your Energy Levels

Another very common symptom of multiple myeloma is fatigue. Fatigue often goes hand-in-hand with anemia, which is very common in multiple myeloma cases. Anemia develops when your body doesn’t produce enough red blood cells to carry oxygen throughout your body. Those malignant plasma cells are responsible for crowding out or even suppressing those healthy red blood cell, and as a result, you feel drained, weak and weary. You may also experience some episodes of confusion.

Your Kidneys

Your kidneys are at risk for damage from multiple myeloma, too. In fact, 20-40% of people diagnosed with multiple myeloma will experience some degree of kidney failure. Why is kidney failure such a common complication? The myeloma cells produce proteins that mix with other proteins in the urine and cause blockages in the tubes within the kidneys (hyperviscosity). The blockages can also damage the kidneys themselves. On top of that, these abnormal proteins can actually contribute to abnormal kidney function and cause inflammation in the kidneys, just by their very presence. People whose kidneys are affected by their multiple myeloma must be extra vigilant about drinking plenty of fluids, because dehydration can exacerbate the problem.

Your Calcium Levels

Another major complication of multiple myeloma is hypercalcemia. Myeloma tumors can elevate the levels of calcium in your blood to dangerous levels, which can then damage organs like your heart, as well as your digestive tract and your muscles. High calcium levels can also exacerbate kidney problems because they contribute to the formation of “casts,” or clumps of combined proteins that cause blockages.

If You Develop Symptoms That Concern You

Men are slightly more likely than women to develop this type of bone marrow cancer, and African American people are twice as likely to develop it than white people. But even if you don’t fit into one of the categories of people deemed at elevated risk, you can still develop multiple myeloma. This type of hematological cancer is the third most common blood cancer in the U.S. It is usually diagnosed after the disease is already at an advanced stage. So, if you start developing symptoms like unusual fatigue or pain in your bones, make an appointment to see your doctor. It might be nothing, but it may still be worth getting checked out.

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Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2022 Feb 23
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THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.
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