Stimulants induce temporary improvements in either mental or physical functions or both, increasing the functioning of the central nervous system. They are also occasionally referred to collectively as 'uppers.'
Stimulants have a long history of human use, with cocaine having been used for thousands of years in its plant form in South America, for the purposes of wakefulness and recreation; it also saw heavy use in the Western world during the 19th century when it was sold as a drug to combat fatigue, as well as being used during medical procedures as a local anesthetic. Amphetamines were first developed and used medically for the same reasons in the early 20th century, and remain heavily prescribed to this day. Today, stimulants are also widely and legally used without prescription across the world in the form of caffeine and nicotine, along with continuing illicit use of other common stimulants.
For more details refer to specific categories or substances.
Further and more serious issues can arise following a binge or during withdrawals from stimulants, see the Quick Guide to Stimulant Comedowns for more information.
The vast majority of stimulants carry a high risk of habituation and addiction when abused. Depending on the chemical and degree of abuse, withdrawal symptoms for a habituated user vary in effect, duration and intensity; see the Quick Guide to Stimulant Comedowns for more information.
Many stimulants are taken by snorting or smoking them. This can cause damage to the nasal lining, oral mucosa and lungs. Ensuring that equipment is clean and sterile can prevent infection as well as making sure pipes are free of cracks and defects. As stimulants place extra strain on the cardiovascular system, it is advised that those who have pre-existing heart conditions or damage avoid stimulant use entirely.
Sleep deprivation is also a common side effect of stimulant use, and prolonged sleep deprivation can lead to more serious conditions such as psychosis or sudden death. Get some sleep every night, and don't drive, operate machinery or perform other dangerous tasks while sleep deprived.