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Side effects of chemotherapy

Chemotherapy drugs cause side effects. Find out more about the general side effects of chemotherapy drugs.

Side effects

There are more than 100 different chemotherapy drugs. This page tells you about the side effects that they may cause. But different drugs cause different side effects. Your doctor or nurse will tell you about specific side effects of your own treatment. 

It’s important to remember that you probably won't get every side effect listed. For some people the effects are mild. Sometimes the side effects of chemo can be unpleasant, but it can help to remember that: 

  • most side effects are short term
  • they’ll begin to go once the treatment has finished
  • you can have medicines to reduce most side effects

Let your nurse or doctor know if you have side effects that are troubling you.

How chemotherapy causes side effects

Chemotherapy damages dividing cells.

Cancer cells divide much more often than most normal cells. So chemotherapy damages cancer cells and can destroy them.

But some types of normal cells divide very often too. This happens in tissues that need a steady supply of new cells, such as the skin, hair and nails.

Chemotherapy can also damage those cells, and this causes side effects. But the damaged normal tissues can repair themselves and recover.

These are some of the most common side effects:

Chemotherapy can make you feel very tired. The tiredness can increase as you go through your treatment and could last for quite a few months after the treatment ends. This is called fatigue.

You might also feel weak and as though you have no energy. This is called lethargy and can be part of fatigue.

Many chemotherapy drugs can make you feel sick or be sick. But anti sickness medicines can usually control this well.

Some drugs can make the lining of your mouth very sore or cause small mouth ulcers. Some can also change your sense of taste for a while.

Some chemotherapy drugs might irritate the lining of your bowel and cause diarrhoea. This usually happens in the first few days after treatment. It can be well controlled with medicines.

Some chemotherapy drugs and some of the medicines to control sickness can cause constipation.

Chemotherapy can affect your appetite. Don't worry too much if you really don't feel like eating for a few days after treatment. You can make up for lost calories later. However, it is important to drink.

Your doctor or nurse can answer any questions about what you should or shouldn't eat. And if you have a problem with diet, digestion or weight loss, talk to your doctor, cancer nurse or dietician.

Chemotherapy drugs often stop the bone marrow from making enough blood cells. The bone marrow makes:

  • white blood cells to fight infection
  • red blood cells to carry oxygen around the body
  • platelets to help the blood to clot and prevent bleeding

During chemotherapy the level of blood cells goes down. You're more at risk of developing infections if your white blood cell count is low. These infections can sometimes be very serious.

So it’s important to tell your hospital treatment team urgently if you have any signs of infection such as: 

  • a high temperature
  • feeling cold and shivery
  • headaches
  • aching muscles
  • a cough
  • a sore throat
  • pain passing urine
  • a lower than normal temperature

Your team will give you contact details to use at different times of the day and night.

You can have the flu vaccination to help reduce your risk of getting flu – unless you’re allergic to eggs, or have had a reaction to the vaccine before, or your doctor has said you shouldn't.

If you’re in the middle of chemotherapy treatment, talk to your specialist about having the vaccination. Your immune system is weaker when you’re having chemotherapy. This means the vaccine might not work quite so well. Your specialist will tell you the best time to have a flu jab to get the greatest chance of protection.

You might feel tired and breathless if your red blood cells are low. And if your platelets are low, you may bruise easily. You can have a transfusion of red blood cells or platelets, if your doctor feels it is necessary.

Some chemotherapy drugs make some of your hair fall out, so that your hair is thinner.

Other chemotherapy drugs make all the hair on your head and body fall out, including eyebrows and eyelashes.

Losing your hair can be distressing. But it's temporary and the hair starts to grow back a few weeks after treatment ends.

Some chemotherapy drugs can make your skin dry and sensitive. Some may cause rashes. You may find that your skin is more likely to burn in the sun or react to chemicals. So be careful when you’re in the sun, and wear at least factor 15 sun protection.

If you have dry skin, avoid swimming while you are having treatment. Some people find that their nails also change and become dry, ridged or brittle or have white lines on them.

Some chemotherapy drugs can damage nerves, especially in your hands and feet. It can make them feel numb or cause feelings like pins and needles.

This usually improves once treatment has ended, but it can take many months. 

Some chemotherapy drugs can affect your hearing. This usually gets better when treatment finishes, but your doctor may reduce the dose of your treatment or change your treatment. 

Tell your doctor or nurse if you have any numbness or changes to your hearing.

Some chemotherapy drugs can cause changes in the way your kidneys, liver, heart or lungs work. The changes are usually temporary and go back to normal when your treatment ends.

But for some people the changes may be permanent. Your doctor can tell you if your drugs are likely to cause any changes.

Some chemotherapy drugs can increase your risk of developing blood clots. Contact your hospital immediately if you become breathless or have swelling in your leg.

Chemotherapy might affect your sex life. You could feel tired and lose interest in sex.

Some chemotherapy drugs can affect fertility. If you’re hoping to have a child, discuss it with your doctor before you start treatment. There might be steps that you and your doctor can take to help keep your fertility.

Late side effects

Most chemotherapy side effects are temporary and disappear once your treatment is over.

But for some people, chemotherapy can cause long term changes in the body. Some of these changes may happen months or many years after the treatment has finished.

Late side effects can include early menopause, infertility, changes to feeling in your hands and feet (peripheral neuropathy) and heart and lung problems. Your doctor and chemo nurse can talk to you about the risk of late side effects with the drugs you're having.

Information and help

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