According to the National Institute on Drug Abuse (NIDA), marijuana is the most commonly abused illegal drug in the United States. Marijuana, which is also referred to as pot, is the dried form of the hemp plant Cannabis sativa. The chemical responsible for eliciting marijuana's effects is delta-9-tetrahydrocannabinol, more commonly referred to as THC.
Brain Effects
According to the National Highway Traffic Safety Administration (NHTSA), smoking marijuana can affect the brain in a number of ways. Individuals who smoke marijuana may experience relaxation, disorientation or euphoria. Lack of concentration, drowsiness, or rapid changes in thought formation or expression are also common effects. Users may feel a sense of well-being, and may develop more acute senses of taste, smell, sight and hearing. Impaired coordination or difficulty with problem solving may also occur. In extreme cases, high doses of marijuana can lead to paranoia, image distortion or psychosis. Such effects may last several days or weeks, depending on the frequency of marijuana use.
Heart Effects
The NIDA notes that within several minutes after smoking marijuana, the heart rate may increase by 20 to 100 percent. This effect may last for up to three hours, and has been demonstrated to increase the risk of heart attack within the first hour following marijuana use, according to the U.S. Drug Enforcement Administration (DEA). Smokers may also experience additional heart problems, including heart palpitations or arrhythmias. Such heart effects may occur more frequently in older individuals, as this population is more susceptible to cardiac issues.
Lung Effects
According to the DEA, marijuana contains over 400 harmful chemicals which may raise the risk of lung infections in certain people. Inhalation of marijuana may also lead certain people to develop a dry mouth or sore throat, notes the NHTSA. Frequent users may develop a persistent cough or symptoms of lung irritation. Abnormal phlegm production or frequent chest illnesses may also occur in individuals who smoke marijuana on a regular basis, according to the NIDA. Some research noted by the NIDA suggests that marijuana use may increase the risk of developing lung cancer; however, these findings have been disputed by separate studies that demonstrate no association between marijuana use and lung cancer.
