The doctor could also bleed a patient using leeches. These are animals that look a bit like slugs but eat blood.

The patient wouldn't feel any pain because the leeches have an anaesthetic in their saliva.

We know today that bleeding people doesn't do them any good, but it was very popular in Henry VIII's time.

Some people would go to be bled often, to try and make sure they didn't fall ill!

Leeches