Effects of Marijuana

Effects of Marijuana

Effects of Marijuana

Negative effects of Marijuana on the body

Physiological Effects of Marijuana – The following information is by Buddy T and the medical review board at About.com Guide.

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:

In addition to the brain, the side effects of marijuana reach many other parts of the body. Marijuana is filled with hundreds of chemicals, and when it is burned, hundreds of additional compounds are produced. When marijuana is inhaled or ingested in some other form, several short-term effects occur. Some of marijuana’s side effects are:

  • Problems with memory and learning
  • Distorted perception
  • Difficulty with thinking and problem solving
  • Loss of coordination
  • Increased heart rate
  • Anxiety, paranoia and panic attacks


The initial effects created by the THC in marijuana wear off after an hour or two, but the chemicals stay in your body for much longer. The terminal half-life of THC is from about 20 hours to 10 days, depending on the amount and potency of the marijuana used. This means that if you take one milligram of THC that has a half-life of 20 hours, you will still have 0.031 mg of THC in your body more than four days later. The longer the half-life, the longer the THC lingers in your body.

The debate over the addictive capacity of marijuana continues. Ongoing studies now show a number of possible symptoms associated with the cessation of marijuana use. These symptoms most commonly include irritability, nervousness, depression, anxiety and even anger. Other symptoms are restlessness, severe changes in appetite, violent outbursts, interrupted sleepor insomnia. In addition to these possible physical effects, psychological dependence usually develops because a person’s mind craves the high that it gets when using the drug.

Beyond these effects that marijuana has, marijuana smokers are susceptible to the same health problems as tobacco smokers, such as bronchitisemphysemaand bronchial asthma. Other effects include dry mouth, red eyes, impaired motor skills and impaired concentration. Long-term use of the drug can increase the risk of damaging the lungs and reproductive system, according to the U.S. Drug Enforcement Agency (DEA). It has also been linked to heart attacks.

Although marijuana is known to have negative effects on the human body, there is a raging debate over the use of medicinal marijuana. Some say that marijuana should be legalized for medical use because it has been known to suppress nausea, relieve eye pressure, decreasemuscle spasms, stimulate appetite, stop convulsions and eliminate menstrual pain. Because of its therapeutic nature, marijuana has been used in the treatment of several conditions including: cancer and AIDS (to supress nausea and stimulate appetite), glaucoma (to alleviate eye pressure), epilepsy (to stop convulsions) and multiple sclerosis (to decrease muscle spasms).

Others believe the negative effects of marijuana usage outweigh the positive. There are currently nine U.S. states that have legalized marijuana for medical purposes: Alaska, Arizona, California, Colorado, Hawaii, Maine, Nevada, Oregon and Washington.

The Munchies

One peculiar phenomenon associated with marijuana use is the increased hunger that users feel, often called the “munchies.” Research shows that marijuana increases food enjoyment and the number of times a person eats each day.

Until recently, the munchies were a relative mystery. However, a recent study by Italian scientists may explain what happens to increase appetite in marijuana users. Molecules called endocannabinoids bind with receptors in the brain and activate hunger.

This research indicates that endocannabinoids in the hypothalamus of the brain activate cannabinoid receptors that are responsible for maintaining food intake.

Short-Term Effects

The short-term effects of marijuana include:

Sometimes marijuana use can also produce anxiety, fear, distrust, or panic.

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:

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:

 The Effects of Marijuana – Cannabis – Weed