Chemotherapy can prolong a person’s life and help eliminate cancer. Its side effects depend on the type of chemo drug involved, but infections, easy bruising or bleeding, and hair loss are some of the more common ones.

Other common side effects of chemotherapy include:

Chemotherapy kills regular cells, as well as cancer cells, and this is why side effects occur. Many people experience these adverse effects, but some people have few or none.

Below, we explore 10 of the more common side effects of chemotherapy.

Effects on the body - chemotherapyShare on Pinterest
Medical illustration by Stephen Kelly

Cancer and the treatment of it can weaken the immune system.

Because chemotherapy kills healthy immune cells, it can make a person more vulnerable to infection. And because the immune system is weakened, any infections may last longer than usual.

Eating plenty of fresh fruits and vegetables, frequently washing the hands, avoiding anyone with an infectious illness, and seeking prompt medical care for signs of an infection can reduce the risk of a serious illness.

Chemotherapy can cause a person to bruise or bleed more easily. Many people having chemotherapy experience this side effect.

Bleeding more heavily than usual can be dangerous. It is a good idea to take precautions, such as wearing gloves when gardening or cutting food. Also, take extra steps to prevent injuries such as falls.

Contact a doctor about any serious wounds or any injuries or bruises that seem to be healing slowly. The American Cancer Society (ACS) recommends contacting the cancer team right away about any bleeding or unexplained bruising during cancer treatment or any blood in stool or urine.

Chemotherapy can damage hair follicles, causing the hair to weaken, become brittle, and fall out. Any hair that regrows may be of a different texture or color. This usually continues until the treatment ends, after which hair almost always regrows.

The authors of one study estimate that 65% of people receiving chemotherapy experience hair loss. There is no guaranteed way to prevent it, but good hair care may slow the loss and promote regrowth.

Here, learn more about hair regrowth after chemotherapy.

Nausea and vomiting can start suddenly. These issues may occur right after each chemotherapy session or days later.

Dietary changes, such as eating smaller meals or avoiding certain foods, can help. Antinausea medications can also help, especially if a person experiences the side effects at predictable intervals, such as immediately after chemotherapy.

Neuropathy is nerve pain caused by damaged nerves. It often affects the hands and feet, causing tingling, numbness, and unusual burning sensations. Some people also experience weakness and pain.

Neuropathy is often worse in people who take certain chemotherapy drugs, according to a 2014 review.

Lotions containing lidocaine or capsaicin may help, but more research is necessary, the ACS note.

Chemotherapy may trigger digestion problems because it can damage cells that help digestion.

Other side effects of chemotherapy, such as nausea, can force people to change their diets, but these changes may also cause or worsen constipation or diarrhea if they are sudden.

Avoiding foods that irritate the stomach may help. And over-the-counter remedies for constipation, such as a stool softener or fiber supplement, can make bowel movements less painful.

In addition, being well-hydrated can reduce the severity of constipation and also prevent dehydration caused by diarrhea.

Chemotherapy can alter the immune system in ways that cause rashes and other skin changes. The drugs can also trigger skin changes directly.

Severe rashes can cause painful, intense itching. If a person scratches until their skin bleeds, there is a risk of infection. Moisturizing lotions and over-the-counter anti-itch creams may help.

Some people develop painful oral sores 1–2 weeks after having some forms of chemotherapy. The soreness can vary in severity, and the sores may bleed or become infected.

A person can try using a nonabrasive toothpaste or a numbing gel. Some people also find relief from rinsing their mouths with warm saltwater. See a doctor for treatment if any sores are very painful or weeping.

Sometimes, chemotherapy can damage the lungs and make it harder to take in enough oxygen. Breathing issues can also result from some types of cancer.

Staying calm, sitting and propping up the upper body with pillows, and practicing pursed lip breathing may help. A doctor may prescribe medication if breathing problems continue.

Call 911, or otherwise contact local emergency services, if anyone has:

  • breathing problems that start suddenly and do not improve
  • a bluish tint to their mouth, nail beds, or skin
  • chest pain
  • weakness or dizziness
  • difficulty speaking

Some side effects of chemotherapy can cause pain. For example, there may be:

  • pain in the mouth and throat, possibly due to oral sores
  • nerve pain
  • pain at the injection site
  • headaches

Pain can also occur as cancer progresses. The ACS encourages people to contact their cancer care team if they experience headaches or pain at an injection or catheter site.

If pain occurs, do not stop having the treatment before discussing this with a doctor. They may be able to help.

Some people experience rare side effects of chemotherapy. Some examples that may signal an emergency include:

  • Hypersensitivity: This involves the immune system reacting to the chemotherapy drug.
  • Extravasation: This is when fluid leaks from a blood vessel into surrounding tissues.
  • Neutropenic typhlitis: This is inflammation of the gut that can affect people with a weakened immune system.
  • Pancreatitis: This is inflammation of the pancreas.
  • Acute hemolysis: This involves the destruction of red blood cells.

The ACS recommend seeking immediate medical care if any of the following occur after chemotherapy:

  • a high fever, usually over 101°F
  • intense chills
  • unusual bleeding or bruising
  • an allergic reaction, which may cause swelling, a rash, or severe itching
  • pain at the injection or catheter site
  • intense headaches or other unusual pain
  • persistent diarrhea, vomiting, or both
  • blood in the stool or urine
  • difficulty breathing, in which case, someone should call 911

Chemotherapy can be an effective treatment for cancer, but it can also have adverse effects.

Before starting the treatment, speak with the doctor about which side effects are most likely, how long they might last, and how severe they might be.

If side effects occur, the cancer care team may be able to help manage them. Treatments and coping techniques can ease and relieve many chemotherapy side effects.