Chemotherapy side effects: blood

Chemotherapy temporarily reduces the rate at which blood cells are produced in your bone marrow.

Blood cells are made in the bone marrow, the spongy tissue found inside the hollow bones of the hips, legs and arms. Your bone marrow makes red blood cells, white blood cells and platelets. 

A blood test will be taken at the beginning of therapy and before each course of treatment. This is to make sure that your ‘blood count’ is satisfactory before you have chemotherapy. Your doctor may also request a ‘blood count’ between treatments.


Possible side effect: Infection (due to low white blood cells)

When symptoms may occur: Usually 7–14 days after chemotherapy

Symptoms include:

  • High temperature
  • Shivering or flu-like symptoms
  • Other signs of infection, such as a sore throat or cough
  • Rash
  • Diarrhoea

What you should do:

  • Check your temperature if you feel unwell
  • Avoid grazing or cutting your skin
  • Contact your hospital immediately if you feel unwell at any time or have a temperature (38°C / 100°F or higher)

There are many types of white blood cells which make up the total white cell count. Their main function is to help your body to fight infection. If your white cell count is low (usually 7 to 14 days after the chemotherapy) you may become prone to infections and take longer to recover from them.

In general, these arise from bacteria within our own bodies, and it is not necessary to avoid crowded places or isolate yourself from others. However, we advise you to keep away from people with serious infections, such as chicken pox.

It is important to keep good personal hygiene. This includes taking daily baths or showers and washing clothes and bed linen regularly. Looking after your mouth will help prevent an infection from developing. Take care to wash your hands well when preparing food, before meals and after using the toilet.

During your treatment try to reduce your risk of developing an infection, for example take care not to graze or cut your skin when gardening, shaving or preparing food. If you do, clean the area with warm water and soap and cover it with a sterile dressing, for example an Elastoplast.

Tell your doctor or nurse if you develop a rash or diarrhoea, as both of these symptoms can be a sign of infection.

Your doctor may prescribe a course of antibiotics to prevent infection during your treatment. Another option is to give you a course of injections of growth factors – proteins that stimulate the production of blood cells. The commonly given growth factor to boost white cells is G-CSF.

The signs of infection (neutropenic sepsis) may be a high temperature, shivering or flu-like symptoms or other signs of infection, such as a sore throat or cough. If you feel unwell at any time or have a temperature (38°C / 100°F or higher) you should contact the hospital immediately as you may need to be admitted for intravenous antibiotics.

If you are on an intensive chemotherapy regimen, you may be given additional advice about diet. You may be advised to avoid certain foods that have been linked with food poisoning in the past, for example soft cheese and under-cooked eggs.


Possible side effect: Anaemia (low red blood cells / haemoglobin)

When symptoms may occur: During your course of chemotherapy

Symptoms include:

  • Tiredness
  • Shortness of breath

What you should do:

  • Eat a diet rich in iron
  • Contact your hospital immediately if you feel very unwell

Red blood cells contain a protein called haemoglobin (Hb), which carries oxygen around the body. If your haemoglobin is low, you may become anaemic and begin to feel very tired and you may look pale. Anaemia may lead to shortness of breath when you exert yourself more than usual, such as when climbing stairs or doing housework.

If during your treatment you begin to feel more tired than normal or become breathless, tell your doctor. Eating a diet rich in iron, for example liver, red meat, fish, eggs and green leafy vegetables, may help to keep your haemoglobin up to its usual level.

If your haemoglobin is very low, you may need to be admitted to hospital for the day or overnight to receive a blood transfusion. Another way of treating anaemia is to stimulate the body to produce more red blood cells. You may be given erythropoietin or EPO, which is a naturally occurring growth factor produced by the kidneys. It stimulates the bone marrow to produce red blood cells.

Bruising or bleeding

Possible side effect: Bruising or bleeding (due to low platelet count)

When symptoms may occur: During your course of chemotherapy

Symptoms include:

  • Gum or nose bleed
  • In rare cases, small groups of red or purple spots on your skin

What you should do:

  • If you are taking drugs such as aspirin or clopidogrel, ask your doctor if you should continue
  • Use a soft toothbrush and an electric razor to prevent damage to your gums and skin
  • Take care not to cut yourself
  • Contact your hospital urgently if you have bruising or bleeding or if groups of red-purple spots appear on your skin
  • Don’t take drugs which could affect your platelets, such as aspirin. Ask your doctor if you’re not sure what to avoid.
  • Take extra care if you are playing sports.

You may need to come into hospital for a platelet transfusion (which is like a blood transfusion but with all the red and white cells removed). Your platelet count can also be corrected by making the rest period between your courses of drugs longer, or by adjusting the doses of the drugs.