system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What is Chemotherapy, and what happens during it?
gpt
it's chemical treatment to combat (usually) cancer growth.  most are in liquid form and are administered intravenously (through a drip in your arm).  a single treatment of chemo may involve receiving several different chemicals in one session, commonly over quite a while (an hour or more).  usually you sit on the ward with others while receiving it or there are some you can receive at home.  depending on the length of course this may be done weekly or fortnightly for several months.  on ward most people chat / read / watch tv while receiving treatment. the combination of chemicals are designed to slow down cell reproduction in your body.   others are designed to kill cancer cells or types of cell in your body.  there are lots of different kinds of chemo for lots of different kinds of cancer.  the side effects usually stem from the slowing cell growth and killing of certain cells : hair loss, nausea/vomiting, constipation, thirst and so on.  it's common to have additional courses of medicine that combat the side effects specifically.