There are numerous sside effects of taking marijuana, among which are; 1. Short term memory problem. 2. Severe anxiety, including fear that one is being watched or or followed (paranoia). 3. Hallucinations. 4. Very strange behavior, seeing things that don't exist and not being able to tell imagination from reality which is medically called "psychosis". 5. Panic. 6.Loss of sense of personal identity. 7. Lowered reaction time. 8. Increased heart rate (risk of heart attack).
Other effects include 9. Problem with coordination ( impairing safe driving 9r playing sports) it occurs to those that drives. 10. Sexual problem (for males). And finally it makes you highly prone to contract sexually transmitted infections than non user ( for females).All of these are short term effects.
The long term effects includes; decline in IQ, poor school performance, impaired thinking and inability to learn and perform complex tasks, potential development of opiate abuse, earl death etc.