Marijuana is the name of a drug derived from the natural plant Cannabis sativa. It is usually formed into a cigarette or joint, using the stems, leaves, flowers and seeds, but may be ingested in many different ways. The main chemical in marijuana that can cause mind-altering effects is THC. According to the National Institute on Drug Abuse (NIDA), marijuana is the most commonly abused illicit drug in the United States. The Centers for Disease Control and Prevention reports that two recently conducted, comprehensive, scientific reviews by the Institute of Medicine of the National Academy of Sciences, the Canadian Addiction Research Foundation, and the World Health Organization (WHO) determined that marijuana has many acute and chronic effects on the user's health.
Immediate Effects
Marijuana use has been shown to have many immediate or acute effects on the body. These can include an increased heart rate, dry mouth, alteration in the sense of time, bloodshot eyes, and a feeling of euphoria. Marijuana can also stimulate the appetite, leaving a user excessively hungry. Because marijuana affects the brain, it can have an acute affect on a person's perception and skilled performance of common activities such as driving, which can be a danger. Marijuana use has also been known to cause episodes of anxiety, hallucination and fear or panic.
Mental Effects
According to The National Institute on Drug Abuse, THC is the main chemical that affects brain function. It passes rapidly from the lungs into the bloodstream, where it reaches the brain and acts upon specific receptors, called cannabinoid receptors. The NIDA goes on to say that the highest density of cannabinoid receptors are found in parts of the brain that influence pleasure, memory, thoughts, concentration, sensory and time perception and coordinated movement. Because of this, mental functions such as problem solving, short-term memory, perception of time and learning are all affected. Chronic use of marijuana can cause the activation of the stress response and creates many of the same problems that long-term use of other illegal drugs does.
Heart
Marijuana can cause problems with the heart, especially for those who are already suffering with some form of heart disease. According to the Missouri Department of Health, marijuana can increase the heart rate as much as 50 percent and cause chest pain for those who have poor blood supply to the heart. The NIDA also reports that marijuana increases the risk of a heart attack nearly five times in the first hour after smoking the drug.
Lungs
The most common way that marijuana is abused is by smoking it, and users breathe deeply and try to hold it in the lungs as long as possible. This practice can be especially harmful to the delicate lung tissues, as the smoke contains some of the same destructive carcinogenic ingredients that tobacco smoke does, but in greater quantity.
