The physical effects of amphetamines are similar to those of other stimulant drugs. When amphetamines are taken by mouth, snorted or smoked, the user usually experiences feelings of euphoria, heightened alertness and greater energy. Heart, breathing and blood pressure rates increase, and sensations of hunger and fatigue are reduced. Heart palpitations may be experienced. The mouth is usually dry and swallowing is difficult, which makes eating food difficult.
Urination is also difficult.
The users' pupils are dilated, and reflexes are faster. Rapid speech often occurs, followed by slurred speech. Extremely high doses may cause people to flush or become pale, and cause a rapid or irregular heartbeat, loss of coordination and even physical collapse. Amphetamine injections create such an increase in blood pressure that strokes, high fevers or heart failure may result. As the drug wears off, feelings of fatigue or depression are experienced.