Many people know that HIV damages and weakens the immune system over time. A damaged immune system makes it difficult for your body to fight off disease. Using crystal and other party drugs is likely to further suppress your immune system. The effects can be harmful for both the short and longer term. In addition to the drugs, the partying lifestyle itself can weaken your immune system. Staying up for long periods of time, not drinking enough water, not eating enough, or not eating the right foods wreck the immune system of any person, even if they are in great health.