Drug-taking is never safe, and the risk is always unknown because the effect has on any person depends on several things that may never be the same twice. Physical Health Problems: Drug use could be more dangerous for those with heart, blood pressure, epilepsy, diabetes, asthma, or liver problems. You may not know you have these. Weight/sex: Drugs affect a lighter person more than a heavier one. Also, because of the different make up of men and women, they have different effects. Frame of mind: If you take drugs when you are feeling worried or down, then you will often feel worse.