Possible side effects associated with marijuana include dizziness, drowsiness and impaired judgement, according to Drugs.com. Marijuana may alter the user's consciousness, and it often makes people feel uninhibited, relaxed, happy and euphoric. It may also cause users to feel sociable.
Marijuana may enhance a person's senses, including taste, sound, sight and smell, states Drugs.com. It may also distort the user's perception of time and space. Marijuana use often causes an increase in appetite, and users may experience bloodshot eyes and dilated pupils. Marijuana may increase the heart rate and pulse.
Because marijuana may impair coordination and concentration, users should not operate machinery or drive a vehicle when high on marijuana, recommends Drugs.com. Some marijuana users may experience negative feelings such as anxiety, self-consciousness, panic and paranoia.
Possible long-term side effects of marijuana include exacerbation of pre-existing heart disease, reduced short-term memory, lowered concentration levels and lung irritation if the marijuana is smoked. Some people may experience difficulties with learning and thinking, which may be resolved after stopping marijuana use.
Some users of marijuana may experience a decreased sex drive after using it long-term, notes Drugs.com. Long-term marijuana use may lower the sperm count in some men and cause irregular periods for women. These sexual side effects may resolve after discontinuing use.