Marijuana is a green, brown, or gray mixture of dried, shredded leaves, stems, seeds, and flowers of the hemp plant. You may hear marijuana called by street names such as pot, herb, weed, grass, boom, Mary Jane, gangster, or chronic. There are more than 200 slang terms for marijuana. All forms of marijuana are mind-altering. In other words, they change how the brain works. They all contain THC, the main active chemical in marijuana. They also contain more than 400 other chemicals. Marijuana's effects on the user depend on the strength or potency of the THC it contains. THC potency of marijuana has increased since the 1970s but has been about the same since the mid-1980s. Marijuana is usually smoked as a cigarette or in a pipe or a bong. Recently, it has appeared in cigars called blunts. THC in marijuana is strongly absorbed by fatty tissues in various organs. Generally, traces of THC can be detected by standard urine testing methods several days after a smoking session. The effects of the drug on each person depend on the user's experience, as well as: how strong the marijuana is, what the user expects to happen, where the drug is used, how it is taken, and whether the user is drinking alcohol or using other drugs. Some people feel nothing at all when they smoke marijuana. Others may feel relaxed or high. Sometimes marijuana makes users feel thirsty and very hungry - an effect called "the munchies." Some users can get bad effects from marijuana. They may suffer sudden feelings of anxiety and have paranoid thoughts. This is more likely to happen when a more potent variety of marijuana is used. The short-term effects of marijuana include: problems with memory and learning; distorted perception (sights, sounds, time, touch); trouble with thinking and problem solving; loss of coordination; and increased heart rate, anxiety. These effects are even greater when other drugs are mixed with the marijuana; and users do not always know what drug...