Hit of heroin = constricted pupils. Withdrawal = dilated pupils. Why is this?

Question

Obviously the narcotic effects of heroin cause pupillary constriciton, but why is it that during withdrawal from heroin a symptom is pupillary dilation?

Answer 1

It's a poison and it causes your brain to do all sorts of weird things.  It puts the brain in a bad state which causes the brain to do weird things when withdrawing.

Please stay away from it and encourage your friends to stay away from it!

Answer 2

From memory, when opiate receptors are stimulated they release chemicals, one of which can have this effect.

Answer 3

thats what happens to that part of the brain when withdrawing..its all in the brain recepters

Answer 4

Morphine can lead to constricted pupils, along with other effects like constipation and euphoria. So when a person is withdrawing, they sort of go into overload in the other direction - dilated pupils, diarrhea, and bad feelings. Think about it this way -- when the body gets used to dealing with constricted pupils and all the sudden the drug is taken away, the body overcompensates and the pupils are more dilated than usual.