Because of their tendency to become addictive, stimulants can be very dangerous drugs to get caught up in. They increase your respiration rate and the speed of your central nervous system. Some of the most common and most likely effects include increased heart and respiratory rates, elevated blood pressure, dilated pupils and decreased appetite. High doses of stimulants can cause rapid or irregular heartbeats, loss of coordination and collapse.

General use of stimulants is also known to cause sweating, blurred vision, dizziness, restlessness, anxiety and delusions.

Symptoms of a stimulant overdose include agitation, increase in body temperature, hallucinations, convulsions, or even possibly death.

Withdrawal symptoms are somewhat hard to detect, but are very serious. These include apathy, long periods of sleep, irritability, depression or disorientation.

Some possible signs of misuse of stimulants include excessive activity, talkativeness, irritability, argumentativeness or nervousness around others. Other harder to notice signs include increased blood pressure or pulse rate, dilated pupils, long periods without sleeping or eating, and euphoria.