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Marijuana's Adverse Effects

Could I become chemically dependent on marijuana?

Yes. When you’re chemically dependent on marijuana, it means you crave it and you need to use more and more to get the same effect. You may have withdrawal symptoms when you stop using it, such as depressed feelings, trouble sleeping or nausea. Because marijuana is a lot stronger now than it used to be, people are also more likely to abuse it and become dependent on it than they were in the past.

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Is marijuana use associated with other drug use?

Yes. Many people use legal drugs like alcohol or cigarettes before they start using marijuana. Marijuana is the most commonly used illegal substance in the United States. It’s often the first illegal drug a person will try. Sometimes marijuana use leads to the use of other illegal drugs.

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What are the common side effects of marijuana use?

The following are some of the common side effects of using marijuana:

  • Trouble remembering things
  • Slowed reaction time
  • Difficulty concentrating
  • Sleepiness
  • Anxiety
  • Paranoia (feeling that people are "out to get you")
  • Altered time perception
  • Red, bloodshot eyes
Using marijuana for a long time makes some people lose interest in school, work, relationships and other activities. It may also cause legal problems. Using marijuana can be especially dangerous in certain situations, such as when you are driving, because your reaction time is slower. This make it more difficult to react to a dangerous situation, which could cause an accident.

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How can marijuana affect me physically?

The following are some of the common physical effects of marijuana:
  • Tremors (shaking)
  • Nausea
  • Headache
  • Decreased coordination
  • Breathing problems
  • Increased appetite
  • Reduced blood flow to the brain
  • Changes in the reproductive organs
Like tobacco, marijuana contains many chemicals that can hurt the lungs and cause cancer. One marijuana cigarette can cause more damage to the lungs than many tobacco cigarettes because marijuana has more tar in it and is usually smoked without filters.

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Other Organizations

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Written by editorial staff.

Marijuana: Medical Implications by JR Hubbard, M.D., Ph.D., SE Franco, M.D. and ES Onaivi, Ph.D. (American Family Physician December 1, 1999,

Reviewed/Updated: 03/08
Created: 09/00