Negative Effects Of Weed: Everything You Need To Know

In many societies marijuana is the second most commonly smoked substance after tobacco.

Whether you’re a recreational user or using marijuana to treat a medical condition, it’s important to know exactly what marijuana does.

Here’s everything you need to know about how weed will make you feel, and the negative effect of weed on your health.

The Effect Of Smoking Weed

In addition to weed’s effect of making people feel high, there are several potential negative effects of marijuana that many people experience shortly after smoking cannabis.

  • Increased Appetite – Often called the “munchies,” most people report feeling hungry after smoking weed. This is why marijuana is used to treat some medical conditions in which appetite is suppressed.
  • Dry Mouth – Another side effect of cannabis for many people is dry mouth. Many people report having an extremely dry mouth after smoking marijuana.
  • Paranoia – A negative effect of weed for many is a feeling of uneasiness after getting high. Many users report feeling paranoid and nervous.
  • Laziness – There is some truth to the stereotype that potheads are lazy, and it’s another common side effect of cannabis. A 2003 survey by found that more than half of of marijuana users reported experiencing a loss of motivation.
  • Dizziness – Another negative effect of weed, for some people, is dizziness. In some cases, it can make people nauseous and even throw up.

Negative Effects of Marijuana on Memory

Negative Effects of Marijuana

Marijuana is believed to negatively affect both short-term and long-term memory.

“When you smoke marijuana, THC and other chemicals enter your bloodstream and travel to the brain,” explained in an article on “Once in the brain, these chemicals alter memory function by activating the endocannabinoid system. This biological system is intricately connected to parts of the brain associated with memory.”

The article explains that CB1 receptors, which respond to THC, are found in the hippocampus, where many memories are processed and stored.

“Long-term marijuana users tend to do worse than people who have never smoked on tests of working memory and verbal memory, even when they aren’t high,” noted the article.

But it seems younger users have more to worry about when it comes to the negative effect of weed on memory.

A 2011 study found that long-term heavy cannabis use can result in memory impairment, particularly for adolescent users.

“Despite relatively brief exposure, adolescent cannabis users relative to their age-matched counterparts demonstrated similar memory deficits to those reported in adult long-term heavy users,” noted the study. “The results indicate that cannabis adversely affects the developing brain and reinforce concerns regarding the impact of early exposure.”

Negative Effect of Weed on Lungs

Just as cigarettes can damage the respiratory system, so can marijuana.

“Anything that lights the plant on fire creates respiratory irritants,” says Dr. Mitch Earleywine, a professor and researcher at the State University of New York at Albany, in an interview with

A 2005 study reveals that THC, like nicotine, contains a “toxic mixture of gases and particulates, many of which are known to be harmful to the lung.”

“Although far fewer marijuana than tobacco cigarettes are generally smoked on a daily basis, the pulmonary consequences of marijuana smoking may be magnified by the greater deposition of smoke particulates in the lung due to the differing manner in which marijuana is smoked,” the study noted.

The study found many negative effects of marijuana on health in those regularly smoking weed, including chronic cough, airway inflammation and even precursors to lung cancer.

But there is limited evidence that marijuana smoking leads to pulmonary disease of respiratory cancer, the study acknowledged.

Interestingly, many cancer patients report marijuana to be highly effective in their treatment.

A 2014 study done in Israel concluded that “cannabis use is perceived as highly effective by some patients with advanced cancer and its administration can be regulated, even by local authorities” but said that “additional studies are required to evaluate the efficacy of cannabis as part of the palliative treatment of cancer patients.”

More than half of the 17,0000 cancer patients in the Israel study reported improvement in pain, general well-being, appetite and nausea. The most common side effect of cannabis was fatigue and dizziness and was described as mild by survey participants. 

Marijuana Addiction

Another negative effect of weed is the potential for addiction.

While the jury is still out on marijuana addiction, research suggests it exists.

A 2011 study looked at the withdrawal side effect of cannabis.

The study followed 49 “dependent cannabis users” who provided daily scores on the “Cannabis Withdrawal Scale” during a two-week period abstaining from weed.

It found that 42 per cent of users who stopped smoking weed felt irritable, had difficulty sleeping and had a decrease in appetite.

“Some people believe the myth that marijuana is not addictive, or that it’s just psychologically addictive. Unfortunately, these false beliefs have been perpetuated by a loose definition of addiction,” noted an article on

“When people think of physical addiction, they tend to think of drugs like heroin. Heroin withdrawal includes severe symptoms such as shaking and vomiting. In contrast, quitting marijuana does not lead to such severe symptoms.”

The American Psychiatric Association (APA) says cannabis withdrawal is caused by use that has been “heavy and prolonged” and is characterized by at least three of the following symptoms:

  • Irritability
  • Anger
  • Nervousness
  • Sleep difficulty
  • Decreased appetite
  • Restlessness
  • Depressed mood
  • Physical symptoms (e.g. stomach pain, shakiness, increased sweating, fever or headaches)

If you are interested in learning more information about marijuana and weed the informational website Beaver Bud has a lot of great resources on the topic especially as it related to purchasing it online in Canada.

To learn about other side effects of various medications make sure to check out our homepage and search for the particular product you are looking for.