Cannabis is highly fat soluble, and absorbed readily and into the brain, liver, lungs and reproductive organs. The absorbed drug can remain stored within the body for several days or even weeks, with extreme use. This is not to say that you will feel the same effects for an extended period, only that the drug is still within the system.

Cannabis is smoked, when smoked in a joint, is generally unfiltered, other than by a twisted piece of cardboard - a "roach" and deeply inhaled, and when it is smoked, the smoke is held in the lungs for several seconds. Cannabis smoke contains carbon monoxide, nitrosamines, benzopyrene, and over 60 cannabinoid compounds. All of these are respiratory irritants and potential carcinogens.

The disadvantages of setting fire to some dried herbs, 10cm away from your face and sucking hot smoke deep into your lungs are obvious. This is particularly bad for you when mixed with known carcinogens such as tobacco. However, cannabis does not have to be smoked in a joint. Several other ways of consumption are:-

Smoking

Bong, Pipe, Chillum, Bucket ,Hot Knife

Other

Used as a cooking ingredient - Space Cakes, "Hash" Browns, etc.

"Herbal" Tea

Research on Cannabis use during pregnancy is inconclusive, although like most substances, Cannabis crosses the placental barrier. Evidence suggests that Cannabis use during pregnancy may be sufficient to produce permanent fetal abnormalities.

Driving performance is impaired, due to altered perception of space and time, and reduced ability to make quick decisions. However, studies have shown that somebody driving under the influence of small amounts of Cannabis can have heightened senses, greater awareness, more concentration and generally will drive at a lower speed, therefore decreasing their likelihood to have an accident.

The whole point of most drugs is to deceive the brain. The active chemical in Cannabis affects your mind is THC - tetrahydrocannabinol. Some areas in the brain have a lot of THC receptors, while other have very few or none. One region of the brain that contains a lot of THC receptors is the hippocampus, the brain's CPU. When THC attaches to receptors in the hippocampus, it weakens short-term memory. No evidence suggests that Cannabis use affects past memories in any way.

Tolerance to a drug develops when increasing doses of a drug are required to produce the same effect. If Cannabis use is infrequent or doses are small, tolerance to the drug is not apparent. After prolonged use, however, it is necessary to ingest more Cannabis to produce the same feelings. The fact that the body stores THC may be a factor in developing tolerance. As with most drugs, a reasonable length break will lower your tolerance as quickly as it was raised.

It is believed that Cannabis is not physically addictive. It can be very addictive in other ways. Like anything else, if you enjoy smoking pot then you are going to want to do it often. You may begin to associate certain things with getting stoned. You probably will find yourself thinking, "I'd better just have a joint before this film starts.....It'll help me get into it"  - I know I do!