What does an overdose do to your body?

The exact mechanism of an overdose depends on the substance being abused, but generally an overdose overwhelms your body with too much of the drug. During a cocaine overdose, for example, you may experience raises in heart rate, blood pressure, body temperature, and your breathing. In general, an overdose takes whatever is enjoyable about a high and increases it so much that it becomes distressing and, in some cases, life-threatening.