What efectts  does marijuana have on the body?

Marijuana is the most commonly used illicit drug in North America. Yet, myths continue regarding its effects on the body and brain. In this article you will learn the basic facts about Marijuana. What it is, what its effects are, what kinds of treatments are available and how to get help if you need it.

What is Marijuana?
Marijuana is a dry, shredded green/brown mix of flowers, stems, seeds, and leaves of the hemp plant Cannabis sativa, it usually is smoked as a cigarette (joint, nail), or in a pipe (bong). It also is smoked in blunts, which are cigars that have been emptied of tobacco and refilled with marijuana, often in combination with another drug. Use also might include mixing marijuana in food or brewing it as a tea. As a more concentrated, resinous form it is called hashish and, as a sticky black liquid, hash oil. Marijuana smoke has a pungent and distinctive, usually sweet-and-sour odor. There are countless street terms for marijuana including pot, herb, weed, grass, widow, ganja, and hash. 

The main active chemical in marijuana is THC (delta-9-tetrahydrocannabinol). It is the way THC interacts with brain chemistry that causes the “high” from marijuana.

Effects on the Brain and Body
When someone smokes marijuana, THC rapidly passes from the lungs into the bloodstream, which carries the chemical to organs throughout the body, including the brain. The short-term effects of marijuana use can include:
• Problems with memory and learning; 
• Distorted perception; 
• Difficulty in thinking and problem solving; 
• Loss of coordination; and 
• Increased heart rate. 

Research findings for long-term marijuana use indicate some changes in the brain similar to those seen after long-term use of other major drugs of abuse – changes that can include withdrawal symptoms when marijuana use is stopped. One study has indicated that a user’s risk of heart attack more than quadruples in the first hour after smoking marijuana. 

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. Many of the extra sick days among the marijuana smokers in the study were for respiratory illnesses. Even occasional 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 greater risk of lung infections, and a greater tendency to obstructed airways. Some of marijuana's adverse health effects may occur because THC impairs the immune system’s ability to fight off infectious diseases and cancer. 

Marijuana use has the potential to promote cancer of the lungs and other parts of the respiratory tract because it contains irritants and cancer causing chemicals. In fact, marijuana smoke contains 50 to 70 percent more cancer causing hydrocarbons than does tobacco smoke. Marijuana users usually inhale more deeply and hold their breath longer than tobacco smokers do, which increases the lungs’ exposure to cancer causing smoke. These facts suggest that, puff for puff, smoking marijuana may increase the risk of cancer more than smoking tobacco.

Research has shown that babies born to women who used marijuana during their pregnancies may have problems with brain development. During infancy and preschool years, marijuana-exposed children have been observed to have more behavioral problems and poorer performance on tasks of visual perception, language comprehension, sustained attention, and memory. In school, these children are more likely to show problems in decision-making skills, memory, and the ability to remain attentive.

Effects on Behavior and Learning
Depression, anxiety, and personality disturbances are all associated with marijuana use. Research clearly demonstrates that marijuana use has potential to cause problems in daily life or make a person’s existing problems worse. Because marijuana compromises the ability to learn and remember information, the more a person uses marijuana the more they are likely to fall behind in growing their intellectual, job, or social skills. In addition, research has shown that marijuana’s negative impact on memory and learning can last for days or weeks after the acute effects of the drug wear off.

Students who smoke marijuana get lower grades and are less likely to graduate from high school, compared to their non-smoking peers. In one study, researchers compared marijuana-smoking and non-smoking 12th-graders’ scores on standardized tests of verbal and mathematical skills. Although all of the students had scored equally well in 4th grade, the marijuana smokers’ scores were significantly lower in 12th grade.



Workers who smoke marijuana are more likely than their coworkers to have problems on the job. Several studies associate workers' marijuana smoking with increased absences, tardiness, accidents, workers' compensation claims, and job turnover. A study of municipal workers found that those who used marijuana on or off the job reported more "withdrawal behaviors"—such as leaving work without permission, daydreaming, spending work time on personal matters, and shirking tasks—that negatively affect productivity and morale.

Is Marijuana Addictive?
Long-term marijuana use can lead to addiction for some people; that is, they use the drug compulsively even though it often interferes with family, school, work, and recreational activities. Drug craving and withdrawal symptoms can make it hard for long-term marijuana smokers to stop using the drug. Feelings of irritability, sleeplessness, and anxiety are reported by people who are trying to quit. 



Treatment
Group therapy that focuses on becoming aware of what feelings or events trigger marijuana use and then coming up with strategies to avoid use has been shown to have the most success. Although there are currently no medications proven to reduce cravings for marijuana, researchers have reported recent discoveries that may make a medication available that can help reduce cravings.