A drug overdose occurs when you consume more drugs than your body can tolerate. Overdose is a relative term, with symptoms that range from the uncontrollable nodding of heroin, to the shakes of crack, cocaine powder and meth, to unconsciousness and death. Drug users are constantly flirting with the risk of a drug overdose. There is a fine line between the high they're seeking and serious injury or death.

Mixing drugs such as heroin, pills and alcohol is the most common cause of death by overdose. Drugs taken together can interact in ways that increase their effects. With depressants (drugs that slow you down) the risk of passing out or stopping breathing increases. With stimulants (drugs that speed you up) the risk of seizures or heart attacks increase. Changes in your health or body can put you at risk for an overdose. Getting sick, or losing weight, affects your tolerance and your body's ability to adjust to the drug. Using alone also increases the chance of fatality overdosing, because there is no one there to call for help or take care of you if you pass out.

All drugs have the potential to be misused, whether legally prescribed by a doctor, purchased over-the-counter at the local drug store, or bought illegally on the street. Taken in combination with other drugs or with alcohol, even drugs normally considered safe can cause death or serious long term consequences. Accidental drug overdose may be the result of misuse of prescription medicines or commonly used medications like pain relievers and cold remedies. Symptoms differ depending on the drug taken.

While many victims of drug overdose recover without long term effects, there can be serious consequences. Some drug overdoses cause the failure of major organs like the kidneys or liver, or failure of whole systems like the respiratory or circulatory systems. Patients who survive drug overdose may need kidney dialysis, kidney or liver transplant, or ongoing care as a result of heart failure, stroke, or coma. Death can occur in almost any drug overdose situation, particularly if treatment is not started immediately.