Question: How do legal drugs cure our body?

Shreesha Bhat answered on 17 Mar 2015:

There are various enzymes, neurotramnsitters, proteins, receptors, etc. which are involved in normal physiological functions of the body. Now, a change in the activity of the normal functions of these substances leads to disorders/diseases in the body (the change can be an increase in function or decrease in function or stopping of the function altogether). For eg. in diabetes type 1: insulin production is stopped, in that case you need to give insulin externally, so insulin would be your drug, in case of diabetes type 2: there is a problem in sensitivity issues regarding insulin receptors, which leads to high blood glucose level, then you need to give something which can improve the sensitivity of insulin receptors, that will be your drug!

In some cases, some enzymes/receptors start overworking, in that case you need to block them, like in hypertension (high blood pressure), you give calcium channel blockers which reduce the level of calcium which in turn gets back the electrolyte balance, and gets the blood pressure under control.

Sometimes, neurotransmitter levels increase/decrease, like in depression dopamine level falls, and in psychosis dopamine level increases, so you give drugs that could increase/derease dopamine levels as per the medical condition.

Hope the examples are easy to understand! Let me know if any confusion!