Fainting, also called syncope, is not one of the most common symptoms of multiple myeloma. However, there are a few medical reasons why a person living with myeloma might faint. Fainting can be scary and potentially lead to injuries. It’s important to understand what causes fainting and how to manage fainting with multiple myeloma.

If you faint for the first time or start fainting more frequently, consult your healthcare team as soon as possible. They can determine the underlying cause and help you arrive at the best way of managing it.

What Causes Fainting in Multiple Myeloma?

There are several reasons why people diagnosed with multiple myeloma might faint.

1. Anemia

Multiple myeloma affects tissues that make red blood cells, so anemia is a common first sign of the condition. Anemia occurs when a person’s body does not have enough red blood cells. The hemoglobin found in red blood cells carries oxygen throughout the body. At least 60 percent to 70 percent of people with multiple myeloma have anemia at the time of their diagnosis.

Anemia in multiple myeloma can lead to the following symptoms:

• Lack of motivation or energy for normal activities
• Dizziness
• Trouble breathing
• Changes in sex drive
• A faster-than-normal heartbeat
• Headache

Anemia can also make you feel lightheaded and faint. Getting treatment for anemia before it becomes severe can help prevent dangerous accidents like fainting.

2. Congestive Heart Failure

Some people with multiple myeloma also get light chain amyloidosis, a condition where certain proteins called amyloids do not fold the right way. The body can’t use these abnormal proteins. Instead, it has to store them somewhere in the body. If these proteins build up in the heart, you may feel dizzy or weak. This can lead to fainting.

One MyMyelomaTeam member has experienced something similar — as they shared, “I have damage to the left ventricle of my heart, which has caused many incidents involving syncope.”

3. High Blood Calcium

Another potential side effect of multiple myeloma is having a higher-than-normal calcium level in the blood. This condition is called hypercalcemia. Myeloma cells cause bones to break down, and because bones have a lot of calcium, the extra calcium builds up in the blood.

Although it’s unusual for hypercalcemia to cause fainting, severe cases can affect heart function and result in fainting. If blood concentrations of calcium continue to rise, hypercalcemia can lead to a coma.

4. Infections

Multiple myeloma and its treatments suppress the immune system. This can raise your chances of getting sick from infections. The infections can range from mild to severe and have many symptoms, like diarrhea, headaches, and fainting. If you have multiple myeloma, it’s important to receive treatment for infections as soon as possible.

5. Medications for Multiple Myeloma

Many of the medications prescribed to treat multiple myeloma and its symptoms can sometimes increase your risk of fainting. Your healthcare provider or pharmacist should alert you ahead of time that you might experience syncope so you can be prepared.

As one member shared, “I’m having a variety of side effects from my myeloma medications. … I’ve been dizzy and even fainted once.” Chemotherapy may cause fainting, too, as it did for a member who explained, “From the time I started chemo, I’ve suffered from drop syncope.”

Changing medications can sometimes lead to fainting, members have shared. One member put it this way: “There was always an underlying issue with changing any of my meds. It set off one of my side effects. In this case, it triggered my syncope.”

Sometimes, syncope caused by changing medications will go away once the body gets used to the new medicines. Other times, the fainting persists.

6. Hyperviscosity Syndrome

When your blood becomes thicker, it is called hyperviscosity. This can make it harder for blood to flow through your veins and reach your brain. Too many myeloma proteins in the blood can cause hyperviscosity.

Hyperviscosity syndrome is very rare in myeloma. Most of the time, hyperviscosity only causes confusion or lightheadedness and dizziness. However, it can sometimes cause syncope or a stroke.

7. Peripheral Neuropathy

Peripheral neuropathy can occur when myeloma or its treatment damages the nerves outside of the spinal cord and the brain. Peripheral neuropathy can affect your balance. It can also affect your blood pressure and lead to fainting.

What Is It Like To Faint With Multiple Myeloma?

Fainting with multiple myeloma can be scary — both for the person with the diagnosis and those who love them. As one MyMyelomaTeam member shared, “Within a period of two weeks, I fainted so many times that my oldest son came and insisted that I get a blood transfusion. Every time that I would faint, my wife would think I was going to die.”

Sometimes, fainting can lead to injuries. One member wrote, “I fainted a while back and fell on my hip, and I thought I broke it.” Potential injuries can lead to added stress on top of the strain you may already feel from caring for your myeloma.

How To Manage Fainting With Multiple Myeloma

Managing syncope can be difficult, but many people diagnosed with multiple myeloma find ways to keep their sense of wellness and quality of life high, even if they faint regularly.

Talk to Your Oncologist

Whether you are experiencing hyperviscosity, congestive heart failure, hypercalcemia, peripheral neuropathy, or an infection, there are steps you can take to manage the condition. The treatment options are different, depending on the condition. Keep in mind that some of these conditions may not be curable, but they may still be manageable.

If you start fainting without any obvious trigger, the most important action you can take is to speak with your doctor. The doctor will help you figure out why you are fainting and determine ways to treat the problem at its source. You may be able to limit the number of fainting episodes or eliminate them altogether.

Tracking your dizziness and fainting episodes is important, especially as you change, stop, or start treatments. Doing so can help your doctor figure out the cause and make the necessary adjustments to your medications.

Change Medications

If you are on a medication that causes fainting, talk to your doctor about whether there are other options you can take instead. You may need to try a few medications before you find one that works well for you without fainting as a side effect.

Move Carefully

Moving carefully and slowly when standing up, walking, climbing stairs, and moving your head may help lessen dizziness and prevent fainting.

Physical and occupational therapists can also help manage fainting. These healthcare professionals teach proper movements to keep you safe when dealing with this symptom. One member described their husband’s positive experience: “At-home occupational and physical therapy has been a godsend. He had so far to go and is improving all the time.”

Occupational therapists can also determine which devices can best assist you during fainting spells. They may suggest installing railings, bars, and other assistive devices in your home to help make living spaces safer when dealing with lightheadedness that leads to fainting.

Tell the people close to you about your history of fainting. This will help them be prepared to help you if an emergency happens.

Talk With Others Who Understand

MyMyelomaTeam is the social network for people with myeloma and their loved ones. More than 28,000 members come together to ask questions, give advice, and share their experiences of life with blood cancer.

Have you fainted after cancer treatment for myeloma? How about from symptoms like high levels of calcium in the blood? Share your experience in the comments below or by posting on your Activities page.