amphetamines are drugs that speed up (stimulate) the nervous system. they can raise a person's heart rate and blood pressure. they increase alertness and may create a feeling of euphoria. they can also cause a loss of appetite and trouble sleeping.
amphetamines may be prescribed to treat conditions such as attention deficit hyperactivity disorder (adhd) and narcolepsy, a sleep disorder. common prescription amphetamines include dextroamphetamine (dexedrine) and lisdexamfetamine (vyvanse).
amphetamines can be misused. they may be sold illegally with names such as speed, meth, ice, crystal, and crank.