Potential Complications of Multiple Myeloma

Medically Reviewed by Arefa Cassoobhoy, MD, MPH on September 20, 2023
5 min read

Multiple myeloma is a type of blood cancer that affects disease-fighting plasma cells. This condition and the treatment for it could cause complications. Some of those problems can be serious or even life-threatening. That’s why it’s important to know the signs of complications and when you should seek medical care.

Most people with multiple myeloma have anemia at some point. In multiple myeloma, cancer cells multiply in your bone marrow. Eventually, they crowd out healthy red blood cells. When this happens, hemoglobin in your red blood cells cannot deliver oxygen throughout your body. That leads to anemia.

Anemia is when levels of hemoglobin in your blood drop too low (10 g/dL or lower). You may feel weak, very tired, out of breath, and dizzy.

Your doctor can test your blood for anemia and prescribe treatments like iron, folate, vitamin B12 supplements, or drugs called red blood cell growth factors. If you develop severe or life-threatening anemia, you may need a blood transfusion.

Multiple myeloma makes you much more likely to get infections. That’s because your bone marrow produces cells that work for your immune system. When cancer cells spread in your marrow that hurts your immune system. It may cause a drop in white blood cells that help you fight infections.

Be on the lookout for signs of infection. They include:

If you think you have an infection, tell your doctor. They may prescribe antibiotics, antifungals, or white blood cell growth factor drugs that boost your immune system.

These tips can help you prevent infections:

  • Wash your hands often.
  • Wash raw fruits and veggies before eating them.
  • Clean and disinfect surfaces in your home.
  • Stay away from people who are sick.
  • Clean your cuts and scrapes.
  • Get any vaccines your doctor recommends.

Multiple myeloma can damage or weaken your bones. You may develop bone pain, bone lesions, or osteoporosis. You may break bones even from minor injuries.

Rapidly growing myeloma cells may form masses in your marrow and damage your bones. These cells also create substances that harm your body’s ability to grow healthy bone.

Calcium and vitamin D supplements, as well as exercise, help bones stay stronger. Your doctor may prescribe drugs called bisphosphonates that slow bone loss.

Bone damage from multiple myeloma can lead to hypercalcemia, or a high level of calcium in your blood. When you have bone damage, calcium can leak from your bones into your bloodstream.

Dangerously high levels of calcium can lead to a coma or heart attack. Seek emergency care if you have these signs:

  • Appetite loss
  • Extreme thirst
  • Frequent need to pee
  • Nausea, vomiting
  • Confusion
  • Restlessness

About half of people with multiple myeloma have kidney damage. If you have kidney damage, you may notice a drop in how much urine you make. Your blood work may show high levels of creatinine, a protein that healthy kidneys usually filter out.

You can take steps to help manage kidney damage. For starters, drink plenty of fluids. Your doctor may also tell you to avoid certain over-the-counter pain medicines called NSAIDs. They may be unsafe for people who have damaged kidneys.

Kidney damage can lead to organ failure. Get medical help, if you have kidney damage plus these symptoms:

Medications for multiple myeloma can cause gastrointestinal (GI) problems like constipation, diarrhea, nausea, or vomiting.

If you have constipation or diarrhea, drink plenty of water to stay hydrated. Eat enough fiber to help you stay regular. Your doctor or nurse can offer other treatments for your GI problems if they continue.

Multiple myeloma puts you at risk for heart and lung problems, including blood clots, pulmonary hypertension, heart failure, and irregular heartbeat (arrhythmias) among other problems. Your risk for these problems is greater if you already have high blood pressure, type 2 diabetes, or high cholesterol. Some medications for multiple myeloma can also increase risk of these complications.

Blood clots. Myeloma drugs like lenalidomide (Revlimid), pomalidomide (Pomalyst), and thalidomide (Thalomid) raise your risk of deep vein thrombosis (DVT) blood clots. If you take these drugs along with dexamethasone, your risk of DVT is six times higher. Clots in your leg arteries can travel up to your lungs, which can be fatal.

Seek emergency care if you have these signs:

Other heart-related side effects. Some myeloma medications can damage your heart tissue, too. You can develop pulmonary hypertension -- a type of high blood pressure that affects the heart and lungs. You could also be at risk for irregular heartbeat, heart failure, and other problems.

Medications that raise your odds for these problems include:

If you already have heart problems before you start treatment for multiple myeloma, make sure your cardiologist is involved in your treatment plan.

Multiple myeloma can affect your mouth or facial bones. Some medications can damage the jawbone. About 30% of people with multiple myeloma have dental problems, including:

Good oral hygiene can help lower your risk of jaw damage.

Before you have a dental procedure, tell your dentist you have multiple myeloma. They can prescribe antibiotics to help prevent mouth infections and help you heal.