Lysergic acid diethylamide (LSD), also known colloquially as acid, is a hallucinogenic drug. Effects typically include altered thoughts, feelings, and awareness of one's surroundings. Many users have visual or auditory hallucinations. Dilated pupils, increased blood pressure, and increased body temperature are typical. Effects typically begin within half an hour and can last for up to 20 hours. It is used mainly as a recreational drug or for spiritual reasons.
