Be careful with weed. Sure, there are people for whom it has a seemingly good effect, but some people are extremely allergic to it (or something). It isn't the same stuff that was around when people smoked in 50 years ago.
Just saying this because I know people who have had to go to the emergency room after one hit, and I also know people who've had the weed stay in their systems for over a month, wreaking havoc on their heart function.
Here are some articles:
http://www.howstuffworks.com/marijuana.htm
HARVARD GAZETTE ARCHIVES
Marijuana Said to Trigger Heart Attacks
By William J. Cromie
Gazette Staff
Marijuana can be hard on the heart. In the first hour after smoking pot, a person’s risk of a heart attack could rise almost five times, according to a Harvard University researcher.
As baby boomers born in the late 1940s and early 1950s reach the age at which heart disease is the leading cause of sickness and death, "we may see an increase in marijuana-associated heart attacks," says Murray Mittleman, an assistant professor at Harvard Medical School and Harvard School of Public Health.
The possible medical uses of the drug are receiving more and more attention. Mittleman thinks such use may be a bad idea for people with heart disease.
The danger exists in the first hour after smoking pot, Mittleman told an American Heart Association meeting in San Diego today (March 2). "It causes the heart rate to increase by about 40 beats a minute," he says. "Blood pressure increases then abruptly falls when the person stands up. This could precipitate a heart attack."
Mittleman noted that, as an immediate trigger for heart attack, pot smoking is nearly twice as dangerous as sex for a sedentary person, exercise for a fit male or female, a tantrum of rage, or a bout of anxiety. But it’s less risky than a spurt of exercise for a couch potato or a snort of cocaine.
Despite the high percentage of people younger than 50 years old who report they use the drug – 12.5 percent – Mittleman doesn’t foresee an epidemic of pot-triggered heart attacks. For a 50-year-old baby boomer without other risk factors, like high blood pressure or high cholesterol, the absolute risk of having a heart attack in the crucial first hour after smoking marijuana is one in 100,000, he says.
These findings come from a study of 3,882 people who survived heart attacks. It was conducted at a number of centers around the country, including Beth Israel Deaconess Medical Center in Boston, where Mittleman works. In the study, 124 people reported using marijuana regularly. Of these, 37 people said they used it within 24 hours of their heart attacks. Nine said they smoked it within an hour of their attacks.
From this data, the researchers conclude that the relative risk of a heart attack jumped 4.8 times within the first hour after smoking, then dropped to 1.7 times in the second hour. That’s still double the risk, but the drop indicates that the danger declines rapidly.
Mittleman admits he can’t explain exactly how pot could trigger a heart attack. It might be due to cannabis, the active ingredient of marijuana, or merely the smoke from a burning plant, he says. Smoking marijuana and tobacco both involve the latter, and both are now implicated in raising the risk of heart disease.
The Health Effects of Marijuana
Negative Health Effects Are Numerous
By Buddy T, About.com Guide
Updated March 05, 2011
Although legalization activists and many marijuana users believe smoking pot has no negative effects, scientific research indicates that marijuana use can cause many different health problems.
Short-Term Effects
The short-term effects of marijuana include:
Distorted perception (sights, sounds, time, touch)
Problems with memory and learning
Loss of coordination
Trouble with thinking and problem-solving
Increased heart rate, reduced blood pressure
Sometimes marijuana use can also produce anxiety, fear, distrust, or panic.
Effects on the Brain
The active ingredient in marijuana, delta-9 tetrahydrocannabinol or THC, acts on cannabinoid receptors on nerve cells and influences the activity of those cells. Some brain areas have many cannabinoid receptors, but other areas of the brain have few or none at all. Many cannabinoid receptors are found in the parts of the brain that influence pleasure, memory, thought, concentration, sensory and time perception, and coordinated movement.
When high doses of marijuana are used, usually when eaten in food rather than smoked, users can experience the following symptoms:
Hallucinations
Delusions
Impaired memory
Disorientation
Effects on the Heart
Within a few minutes after smoking marijuana, the heart begins beating more rapidly and the blood pressure drops. Marijuana can cause the heart beat to increase by 20 to 50 beats per minute, and can increase even more if other drugs are used at the same time.
Because of the lower blood pressure and higher heart rate, researchers found that users' risk for a heart attack is four times higher within the first hour after smoking marijuana, compared to their general risk of heart attack when not smoking.
Effects on the Lungs
Smoking marijuana, even infrequently, can cause burning and stinging of the mouth and throat, and cause heavy coughing. Scientists have found that regular marijuana smokers can experience the same respiratory problems as tobacco smokers do, including:
Daily cough and phlegm production
More frequent acute chest illnesses
Increased risk of lung infections
Obstructed airways
Most marijuana smokers consume a lot less cannabis than cigarette smokers consume tobacco, however the harmful effects of smoking marijuana should not be ignored. Marijuana contains more carcinogenic hydrocarbons than tobacco smoke and because marijuana smokers typically inhale deeper and hold the smoke in their lungs longer than tobacco smokers, their lungs are exposed to those carcinogenic properties longer, when smoking.
What About Cancer?
Although one study found that marijuana smokers were three times more likely to develop cancer of the head or neck than non-smokers, that study could not be confirmed by further analysis.
Because marijuana smoke contains three times the amount of tar found in tobacco smoke and 50 percent more carcinogens, it would seem logical to deduce that there is an increased risk of lung cancer for marijuana smokers. However, researchers have not been able to definitively prove such a link because their studies have not been able to adjust for tobacco smoking and other factors that might also increase the risk.
Studies linking marijuana smoking to lung cancer have also been limited by selection bias and small sample size. For example, the participants in those studies may have been too young to have developed lung cancer yet. Even though researchers have yet to "prove" a link between smoking pot and lung cancer, regular smokers may want to consider the risk.
Other Health Effects
Research indicates that THC impairs the body's immune system from fighting disease, which can cause a wide variety of health problems. One study found that marijuana actually inhibited the disease-preventing actions of key immune cells. Another study found that THC increased the risk of developing bacterial infections and tumors.
Effects of Exposure During Pregnancy
Several studies have found that children born to mothers who used marijuana during pregnancy exhibit some problems with neurological development. According to those studies, prenatal marijuana exposure can cause:
Altered responses to visual stimuli
Increased tremulousness
Problems with sustained attention and memory
Poor problem-solving skills