I did a little research on marijuana and I wonder if all the people here who seem to think consuming drugs is normal have ever done so...
Cancer
It's hard to know for sure whether regular marijuana use causes cancer. But it is known that marijuana contains some of the same, and sometimes even more, of the cancer-causing chemicals found in tobacco smoke. Studies show that someone who smokes five joints per day may be taking in as many cancer-causing chemicals as someone who smokes a full pack of cigarettes every day (15) .
Lungs and airways
People who smoke marijuana often develop the same kinds of breathing problems that cigarette smokers have: coughing and wheezing. They tend to have more chest colds than nonusers. They are also at greater risk of getting lung infections like pneumonia.
Immune system
Animal studies have found that THC can damage the cells and tissues in the body that help protect against disease. When the immune cells are weakened you are more likely to get sick.
Some studies show that when people have smoked large amounts of marijuana for years, the drug takes its toll on mental functions (4). Heavy or daily use of marijuana affects the parts of the brain that control memory, attention, and learning. A working short-term memory is needed to learn and perform tasks that call for more than one or two steps.
Smoking marijuana causes some changes in the brain that are like those caused by cocaine, heroin, and alcohol. Scientists are still learning about the many ways that marijuana can affect the brain.
One study has indicated that a user's risk of heart attack more than quadruples in the first hour after smoking marijuana(8). The researchers suggest that such an effect might occur from marijuana's effects on blood pressure and heart rate and reduced oxygen-carrying capacity of blood.
A study of 450 individuals found that people who smoke marijuana frequently but do not smoke tobacco have more health problems and miss more days of work than nonsmokers(9). Many of the extra sick days among the marijuana smokers in the study were for respiratory illnesses.
Even infrequent use can cause burning and stinging of the mouth and throat, often accompanied by a heavy cough. Someone who smokes marijuana regularly may have many of the same respiratory problems that tobacco smokers do, such as daily cough and phlegm production, more frequent acute chest illness, a heightened risk of lung infections, and a greater tendency to obstructed airways(10). Smoking marijuana increases the likelihood of developing cancer of the head or neck, and the more marijuana smoked the greater the increase(11). A study comparing 173 cancer patients and 176 healthy individuals produced strong evidence that marijuana smoking doubled or tripled the risk of these cancers.
Marijuana use also has the potential to promote cancer of the lungs and other parts of the respiratory tract because it contains irritants and carcinogens(12, 13). In fact, marijuana smoke contains 50 to 70 percent more carcinogenic hydrocarbons than does tobacco smoke(14). It also produces high levels of an enzyme that converts certain hydrocarbons into their carcinogenic form - levels that may accelerate the changes that ultimately produce malignant cells(15). Marijuana users usually inhale more deeply and hold their breath longer than tobacco smokers do, which increases the lungs' exposure to carcinogenic smoke. These facts suggest that, puff for puff, smoking marijuana may increase the risk of cancer more than smoking tobacco.
Some of marijuana's adverse health effects may occur because THC impairs the immune system's ability to fight off infectious diseases and cancer. In laboratory experiments that exposed animal and human cells to THC or other marijuana ingredients, the normal disease-preventing reactions of many of the key types of immune cells were inhibited(16). In other studies, mice exposed to THC or related substances were more likely than unexposed mice to develop bacterial infections and tumors(17, 18).
Marijuana may also increase your risk for certain infections, including herpes and a variety of other bacterial, viral and fungal infections.
In particular, a fungus sometimes found in marijuana called aspergillus is thought to be the cause of possible infections.
Recent studies suggest that smoking marijuana may also decrease the ability of cells in the lung to destroy candida and bacteria.
Studies in animals and humans show that marijuana may further lower the levels of hormones, including testosterone.
Uli,43,Germany