Marijuana Abuse

When marijuana is smoked it immediatley begins to effect the body. When the drug enters the body the effects last for 1-3 hours. But the main drug in marijuana, THC, stays in the system for 2 weeks to 2 months. It can also be consumed in food and/or drink, but the effects only last on average about an hour. Within minutes after the smoke is inhaled into the body the heart rate increases 20-50 beats per minute. When THC enters the brain the person begins to feel a "high" feeling. It stimulates brain cells to release the chemical dopamine. Heavy users of this drug become impaired in being able to create and/or recall memories. THC also disrupts cordination, balance and reaction time. In the National Highway Traffic Safety Administration research it shows that only a small amount of marijuana in a persons system will impair their driving skills. Combined with alcohol this can be deadly. When a person has marijuana and alcohol in their system it is hard for them to stop drinking because the marijuana stops the feeling of being full and feeling upset in the stomach, so a person can not tell how many drinks they have really had. When a marijuana user smokes and/or chews tobacco also, it makes quiting tobacco that much harder. A study of 450 individuals showed that people who use marijuana on a regular basis, but do not use tobacco, have more problems and miss more days of work and/or school than regular tobacco smokers who do not use marijuana. Marijuana increases the chance of getting cancer in the head or neck, the more marijuana used, the more likely you are to get these cancers. Marijuana smoke contains more than 50-70% more carcinogenic hydrocarbons than tobacco smoke does. Many doctors say that the THC in marijuana damages the immune system and makes it harder to fight off diseases and cancer.

Source
http://www.nida.nih.gov/researchreports/marijuana/Marijuana3.html