Side Effects of Chemotherapy

Chemotherapy treats many types of cancer effectively. But like other treatments, it often causes side effects. The side effects of chemotherapy are different for each person. They depend on the type of cancer, location, drugs and dose, and your general health.

Why does chemotherapy cause side effects?

Chemotherapy works on active cells. Active cells are cells that are growing and dividing into more of the same type of cell. Cancer cells are active, but so are some healthy cells. These include cells in your blood, mouth, digestive system, and hair follicles. Side effects happen when chemotherapy damages these healthy cells.

Can side effects be treated?

Yes. Your health care team can help you prevent or treat many side effects. Today, many more medications are available for side effects than in the past. Preventing and treating side effects is called palliative care or supportive care. It is an important part of cancer treatment. Doctors and scientists work constantly to develop drugs, drug combinations, and ways of giving treatment with fewer side effects. Many types of chemotherapy are easier to tolerate than they were a few years ago.

Care after cancer treatment is important

Getting care after treatment ends is important. Your health care team can help you treat long-term side effects and watch for late effects. This is called follow-up care. Your follow-up care might include regular physical examinations, medical tests, or both.

Doctors often recommend chemotherapy as a treatment for cancer. Chemotherapy uses drugs that kill dividing cancer cells and prevent them from growing.

How chemotherapy drugs are given

Chemotherapy drugs can be given in different ways, including:

  • Chemotherapy infusions. Chemotherapy is most often given as an infusion into a vein (intravenously). The drugs can be given by inserting a tube with a needle into a vein in your arm or into a device in a vein in your chest.
  • Chemotherapy pills. Some chemotherapy drugs can be taken in pill or capsule form.
  • Chemotherapy shots. Chemotherapy drugs can be injected with a needle, just as you would receive a shot.
  • Chemotherapy creams. Creams or gels containing chemotherapy drugs can be applied to the skin to treat certain types of skin cancer.
  • Chemotherapy drugs used to treat one area of the body. Chemotherapy drugs can be given directly to one area of the body. For instance, chemotherapy drugs can be given directly in the abdomen (intraperitoneal chemotherapy), chest cavity (intrapleural chemotherapy) or central nervous system (intrathecal chemotherapy). Chemotherapy can also be given through the urethra into the bladder (intravesical chemotherapy).
  • Chemotherapy given directly to the cancer. Chemotherapy can be given directly to the cancer or, after surgery, where the cancer once was. As an example, thin disk-shaped wafers containing chemotherapy drugs can be placed near a tumor during surgery. The wafers break down over time, releasing chemotherapy drugs. Chemotherapy drugs may also be injected into a vein or artery that directly feeds a tumor.
Common side effects of Chemotherapy

Different drugs cause different side effects. Certain types of chemotherapy often have specific side effects. But each person’s experience is different.

Tell your doctor about all the side effects you notice. For most types of chemotherapy, side effects do not show how well treatment is working. But they can for some types of drugs called targeted therapies.

Below is a list of common side effects of traditional chemotherapy.

Fatigue. Fatigue is feeling tired or exhausted almost all the time. It is the most common side effect of chemotherapy.

Pain. Chemotherapy sometimes causes pain. This can include:

  • Headaches
  • Muscle pain
  • Stomach pain
  • Pain from nerve damage, such as burning, numbness, or shooting pains, usually in the fingers and toes

Mouth and throat sores. Chemotherapy can damage the cells inside the mouth and throat. This causes painful sores in these areas, a condition called mucositis.

Mouth sores usually happen 5 to 14 days after a treatment. The sores can get infected. Eating a healthy diet and keeping your mouth and teeth clean can lower your risk of mouth sores. Mouth sores usually go away completely when treatment ends.

Diarrhea. Some chemotherapy causes loose or watery bowel movements. Preventing diarrhea or treating it early helps keep you from getting dehydrated (losing too much body fluid). It also helps prevent other health problems.

Nausea and vomiting. Chemotherapy can cause nausea (feeling sick to your stomach) and vomiting (throwing up). Whether you have these side effects, and how much, depends on the specific drugs and dose. The right medications given before and after each dose of chemotherapy can usually prevent nausea and vomiting.

Constipation. Chemotherapy can cause constipation. This means not having a bowel movement often enough or having difficult bowel movements. Other medicines, such as pain medication, can also cause constipation. You can lower your risk of constipation by drinking enough fluids, eating balanced meals, and getting enough exercise.

Blood disorders. Your bone marrow is the spongy tissue inside your bones. It makes new blood cells. Chemotherapy affects this process, so you might have side effects from having too few blood cells. Usually the number of blood cells return to normal after chemotherapy is complete. But during treatment, low numbers of blood cells can cause problems and must be watched closely.

Nervous system effects. Some drugs cause nerve damage. This can cause the following nerve or muscle symptoms:

  • Tingling
  • Burning
  • Weakness or numbness in the hands, feet, or both
  • Weak, sore, tired, or achy muscles
  • Loss of balance
  • Shaking or trembling
  • Stiff neck or headache
  • Problems seeing, hearing, or walking normally
  • Feel clumsy

These symptoms usually get better with a lower chemotherapy dose or after treatment. But damage is sometimes permanent.  

Changes in thinking and memory. Some people have trouble thinking clearly and concentrating after chemotherapy. Cancer survivors often call this chemobrain. 

Sexual and reproductive issues. Chemotherapy can affect your fertility. For women, this is the ability to get pregnant and carry a pregnancy. For men, fertility is the ability to make a woman pregnant. Being tired or feeling sick from cancer or treatment can also affect your ability to enjoy sex. 

Chemotherapy can also harm an unborn baby, called a fetus. This is especially true in the first 3 months of pregnancy, when the organs are still developing. If you could get pregnant during treatment, use effective birth control. If you do get pregnant, tell your doctor right away.

Appetite loss. You might eat less than usual, not feel hungry at all, or feel full after eating a small amount. If this lasts through treatment, you may lose weight and not get the nutrition you need. You may also lose muscle mass and strength. All these things make it harder to recover from chemotherapy.

Hair loss. Some types of chemotherapy cause hair loss all over your body. It may come out a little at a time or in large clumps. Hair loss usually starts after the first several weeks of chemotherapy. It tends to increase 1 to 2 months into treatment. Your doctor can predict the risk of hair loss based on the drugs and doses you are receiving.

Heart health. Some types of chemotherapy can affect your heart. It can help to check your heart before treatment. This way, doctors can tell if treatment causes problems later. One common test is an echocardiogram (echo). This test uses ultrasound waves to create a moving picture of the heart.  

Long-term side effects. Most side effects go away after treatment. But some continue, come back, or develop later. For example, some types of chemotherapy may cause permanent damage to the heart, lung, liver, kidneys, or reproductive system. And some people have trouble with thinking, concentrating, and memory for months or years after treatment.

Nervous system changes can develop after treatment. Children who had chemotherapy may develop side effects that happen months or years after treatment. These are called late effects. Cancer survivors also have a higher risk of second cancers later in life.

Tips for Managing Chemotherapy Side Effects

Nausea and Vomiting
You can help ease nausea and vomiting by changing your eating patterns:

  • Eat five or six small meals rather than three big ones.
  • Take your time when you eat and drink.
  • Drink an hour before or after meals rather than when you eat. Apple juice, tea, and flat ginger ale may help.
  • Avoid strong-smelling foods. Strong smells can sometimes bring on nausea.
  • Pass on sweets, and fried and fatty foods, which may make you queasy.
Your doctor may prescribe anti-nausea drugs. These are usually given to prevent you from feeling nauseous. Talk to your doctor about the best anti-nausea drug for you. Sometimes you may need to try different drugs until you find one that helps you the most.
Taste Changes
Some types of chemotherapy can affect your sense of taste. Follow these tips to better enjoy eating:

  • Red meat may taste different to you. If so, try poultry, mild-flavored fish, or dairy products instead.
  • If your favorite foods taste different, avoid them so you don’t develop a distaste for them.
  • If foods taste metallic, try eating with plastic utensils.
  • Use a sweet marinade to help bring flavor to your main dish.
'Chemo Brain'
Some people feel short-term mental fog after treatment. To manage so-called “chemo brain,” try these tips:

  • Use a daily planner to help you manage — and remember — appointments, names, addresses, numbers, and to-do lists.
  • Keep your brain active. You could take a class, attend lectures, or do word puzzles.
  • Eat well, and get enough exercise and sleep.
  • Focus on one thing at a time.
You may find yourself feeling tired, but there are ways to help manage that.

  • Rest or take short naps during the day.
  • Exercise. A short walk may boost your energy.
  • Ask family or friends for help when you need it.
  • Focus your energy on important things.

If you just can’t shake the feeling of being tired, check with your doctor. In some patients, chemotherapy can lead to anemia and low red blood cell counts. Your doctor can test your blood and treat you if necessary.

Hair Loss
Some, but not all chemo treatments, can lead to hair loss. If your treatment does, here’s what you can do:

  • After chemotherapy, use soft-bristle brushes. Avoid hair products with harsh chemicals, such as hair dyes or permanents.
  • Cutting your hair short may make it look thicker and fuller.
  • If you think you’d want a wig, shop for it before you lose your hair. That way, you can better match it to your hair.
  • Wear a hat or scarf in cold weather, and use sunscreen to protect your scalp from the sun.
  • Your scalp may feel tender and dry. Wash it with mild moisturizing shampoos and conditioners, and apply gentle lotions.
Sun Sensitivity
You may be more sensitive to sunlight in the months following treatment.

  • Stay out of direct sunlight, especially when the sun’s rays are the strongest (between 10 a.m. and 4 p.m.).
  • Use sunscreen (look for a “broad-spectrum” product with a SPF of 30 or higher) and lip balm with sunscreen.
  • Wear long pants, long sleeve shirts, and wide-brimmed hat when outdoors.