This page was reviewed under our medical and editorial policy by
Maurie Markman, MD, President, Medicine & Science
This page was updated on April 29, 2022.
Feeling dizzy, losing your balance or falling down can be frightening. These may occur with certain cancers or cancer treatments, but there are things you may be able to do to avoid these discomforts or any sudden stumbles.
The first step is to speak with your care team. They may be able to work with you to figure out what’s causing your dizziness or balance issues. It may just be a simple lifestyle change you need, but it’s important to determine if your dizziness is a sign of a more serious concern.
Below are some potential reasons behind this symptom.
Dehydration: If you’re experiencing diarrhea, nausea and vomiting from your treatments or the underlying cancer, it’s easy to become dehydrated. Dehydration may cause a steep, sudden drop in blood pressure that may leave you feeling dizzy and at risk for passing out.
Getting up too quickly: The medical term for this is orthostatic hypotension. It happens to many people for a variety of reasons. If you’re dizzy from cancer or its treatment, changing positions too quickly may make it worse.
Anemia: Marked by abnormally low levels of red blood cells, anemia may occur as a side effect of chemotherapy or as a symptom of some cancers, and may cause dizziness.
Heart disease: While rare, some heart problems may develop after cancer treatment, such as irregular heartbeats, damage to heart valves or heart failure. These may make you feel dizzy. Heart-related side effects are more likely if you’re 60 or older, a young child or a female. Heart damage is also more common if you were treated with high doses of chemotherapy drugs called anthracyclines. High-dose radiation to the chest may raise the risk for heart disease after cancer treatment.
Low blood sugar: When blood sugar, or glucose, dips too low, you may feel symptoms, including anxiety, sweating and dizziness. It’s most often related to diabetes—a sign of too-aggressive blood sugar management. Low blood sugar may result from a tumor in the pancreas, the organ that makes the hormone tasked with regulating blood sugar or glucose levels (insulin). In very rare cases, low blood sugar may result from a tumor that makes a similar hormone to insulin called insulin-like growth factor.
Infection: Cancer and cancer treatment weaken the immune system, making it unable to fight off infection. An infection may cause dizziness or loss of balance.
Anxiety and stress: Learning that you have cancer and navigating its treatment may affect your mental health, and anxiety and stress may lead to dizziness.
Cancer in the brain: Some cases of dizziness or balance problems may signal the location of cancer. Dizziness may occur as a result of a brain tumor, for example. Cancers in the cerebellum—the lower back part of the brain that controls coordination—often cause these symptoms.
Certain therapies: Sometimes cancer treatment may be directly responsible for dizziness and balance issues. Dizziness may be a side effect of chemotherapy and radiation therapy. Dizziness is more likely to occur if the radiation is directed at the brain, spine or other parts of the body related to the nervous system.
Medications that may lead to dizziness include:
You may be taking some of these medications to better cope with how cancer is affecting you mentally and physically. You may be taking others for conditions unrelated to cancer. (People age 65 and older are more likely to have one or more chronic health problems.)
Some drug-related dizziness resolves within a few days or weeks. Stay one step ahead by asking your doctor or pharmacist about possible medication side effects. If the dizziness becomes intolerable, you may be able to switch to a different medicine.
Once you and your doctor have identified the cause of your dizziness and balance problems, you’ll be able to address it directly. For example, if anxiety or stress is to blame, speaking with a mental health professional may help you overcome these debilitating symptoms. If anemia is the problem, your doctor may suggest iron therapy, a blood transfusion, shots of erythropoiesis-stimulating agents, or other drugs to reverse it.
In general, and especially during cancer treatment, drinking enough fluids keeps you well hydrated. Aim for a daily intake of eight to 12 glasses of water or other fluids (8 ounces each). Remember that beverages with caffeine such as coffee, tea and soda, as well as alcohol, may lead to dehydration or make it worse, not better.
Taking precautions also makes a difference. If you feel dizzy when you stand up quickly, take your time getting up and hold on to a sturdy chair or table for balance when you do. Consider a walking stick or cane until you regain your balance.
In some situations, such as a loss of muscle tone and/or coordination, your doctor may refer you to an occupational, physical or rehabilitation therapist to help you regain balance and learn coping techniques and better body mechanics to use at home or on the job. A therapist may also suggest mobility aids, such as a walker or shower chair, to keep you safe from falls.
There also are over-the-counter and prescription drugs to help reduce dizziness and prevent falls. Ask your doctor about:
Some of these medications may also prevent nausea and vomiting from chemotherapy—and stave off dehydration and related dizziness. Never take anything without clearing it with your doctor first, as it may interfere with some cancer treatments.
Relieving your dizziness may involve some troubleshooting, but there are ways to help you get back to doing the things you enjoy comfortably.