system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: why does the human body experience such intense reactions from drug withdrawals? What exactly is happening?
gpt
Drugs are substances that are chemically similar to stuff our body uses for internal communication. Morphines for example are similar to endorphines (hence the name, endo=inner)

If you take the drug the job of that internal substance gets done way too much. But your body isn't dumb. It knows thats too much, so it stops producing that internal chemical on its own when you supply way too much from the outside. The receptors also get more resistant from the constant firing, wich is why you build a tolerance.

Now if you stop doing the drug the exact opposite happens. Now there isn't enough of that chemical in your body, and it takes a while for your body to readjust.

And thats pretty dangerous, as these chemicals control basically everything your body does, including bloodpressure, breathing, emotions, ...