Inside our bones, a spongy material called bone marrow is constantly creating stem cells.

All blood cells begin as stem cells, and as they divide, they develop into the three different types of blood cells.

These are red blood cells, white cells and platelets.

Each type of cell has a different job.

Red blood cells carry oxygen around the body.

To do this they use something called haemoglobin. This is what makes your blood red.

If you don’t have enough red blood cells circulating oxygen in your body you become anaemic.

Anaemia can make you feel tired and breathless, and you might look pale.

White blood cells are part of our immune system, and they help fight off infection.

If you don’t have enough white cells you’re more likely to pick up an infection.

Platelets help prevent bleeding and help blood to clot.

When a wound is bleeding, platelets gather at the wound and help form a clot to stop the bleeding.

If you don’t have enough platelets in your blood, you’ll bruise more easily and you might have bleeding gums, rashes and nose bleeds.

Cancer treatments can affect all types of blood cells and so regular blood tests are taken to check your blood count.

Any problems can usually be treated easily.

For more information, help, or if you just want a chat, call the Macmillan Support Line on 0808 808 00 00

Or visit mamillan.org.uk