Why do I bruise so easily now?

Platelets are the part of the blood that stops bleeding, and many treatments lower them for a while. Low platelets show up as bruises you do not remember getting, bleeding gums, or nosebleeds.

We check this in your blood before each treatment. Some things we need to know straight away. Bleeding that does not stop after ten minutes of pressure. Blood in your urine or stool. A bad headache after a knock.

Written by two physicians. Checked against patient information from the US National Cancer Institute and Cancer Research UK.