Addiction to anything can create a problem whether a small one or big. Addictions to drugs have severe effects on health of abuser. There are many reasons for addiction to drugs and no one can specially say this is the root cause for drug addiction.
Person can suffer from various problems due the addiction to drugs, knowingly or unknowingly. Brain is most crucial part of the body and with addiction to drugs it can be affected. Many diseases are found with addiction to drugs. We mainly survive with proper functioning of brain, if that is affected the entire health of the person and life is affected.
Brain reward system gets damaged and functioning of the brain including the other parts is affected. Vomiting, nausea, running nose, muscle pains are few short term effects due to drug abuse. These drugs also affect the memory power of the person. The people can suffer from long term diseases like nervous collapse, respiratory problem, and heart problems and can even die in minutes.