The Short-Term and Long-Term Effects of Weed (Marijuana)

side effects of smoking weed

Marijuana, also known as weed, herb, pot, grass, bud, ganja, Mary Jane, and a host of other street names, is the most commonly used illicit drug in the United States. In 2015, more than 11 million people, aged 18–25 years, were found to have used weed in the past year.1 But though widespread among the younger crowd, weed use isn’t limited to them alone. Nearly 49% of Americans say they have tried the drug at some point or the other.2

While marijuana is also used in some states for medicinal purposes – as a narcotic drug or for pain relief in conditions like advanced cancer, the illegal use for recreational purposes is more rampant. With the number of users only expected to go higher, it’s time to take stock of the possible effects of marijuana on your physical and mental health.

Marijuana The Herb

Marijuana or weed is a greenish-gray mixture of dried, shredded leaves and flowers of Cannabis Sativa, the hemp plant. The feeling of euphoria that comes from weed use – and which pot smokers crave for – can be traced to a psychoactive chemical found in the herb called delta-9-tetrahydrocannabinol (THC) in the herb.3

This mind-altering substance is found in resin produced primarily by the leaves and buds of the female cannabis plant. Besides THCs, weed contains more than 500 other chemicals, including more than a 100 compounds called cannabinoids. These compounds are also chemically related to THC.4


The Immediate Or Short-Term Side Effects Of Weed Use

Smoking weed might give you a high but other less welcome side effects will also kick in, some almost immediately! They include:

  • Dryness of the eyes, mouth, and throat (commonly referred to as “cotton-mouth”)
  • Bloodshot eyes, as the blood vessels in the eyes expand
  • Loss of coordination
  • Hallucinations
  • Paranoia
  • Rapid heart rate
  • Low blood pressure
  • Slowed digestion
  • Dizziness
  • Increased appetite (the “munchies”)

The side effects can last an hour or two and, in some cases, even linger for 6–8 hours.5 6


The Long-Term Effects Of Weed Use

Aside from these immediate changes in your body, long-term or chronic users face the possibility of serious health issues.

1. Mental Health

Weed affects brain function and compromises your ability to do complex tasks.


No matter how little or often you smoke or use pot, drug abuse affects brain function and compromises your ability to do complex tasks. Excessive weed use can even limit your brain’s capacity to store and retrieve information. Additionally, there’s a high chance of irreparable damage to your memory functions, as well as your math and verbal skills.7

Studies provide ample evidence of brain damage due to weed use. In 2012, researchers in Australia performed brain scans on a group of chronic weed users. The scans were compared to brains of people who had never used the herb. The drug users’ brains showed structural changes that were similar to those found in people with schizophrenia.8


In another study, scientists exposed young mice to low THC doses for 20 days. As the mice grew older, they showed abnormal brain functions and impaired cognitive abilities. However, when this test was performed on adult mice, the same test results were not seen, indicating that marijuana abuse could be far more damaging to the brain when a person is still young.9

The continued use of marijuana has also been linked to an increased prevalence of anxiety, schizophrenia, depression, and suicidal thought.10


2. Heart Health

Weed increases your heart rate drastically

One common after-effect of weed is that your heart rate increases drastically and may remain elevated for up to 3 hours. One study suggests that in the immediate aftermath or the first hour after using weed, your chances of suffering a heart attack may increase by up to 4.8 times!11


3. Lung Health

Smoking Pot exposes your lungs to a high amount of carcinogens

Ever wondered why your eyes become bloodshot or red when you get high on weed? Here’s how. After you smoke pot, your bronchial passage relaxes and becomes enlarged. As a result, the blood vessels in the eyes expand, thereby making your eyes look red.

Whether you smoke marijuana, tobacco, or both, you’re exposing your lungs to smoke containing a high amount of carcinogens. This can result in respiratory problems, such as persistent coughing and phlegm production, acute chest illnesses, and a heightened risk of lung infections.

Weed is usually smoked unfiltered and the fact that it burns at a high temperature can be detrimental to your lungs’ health. As a marijuana user, you tend to take longer, deeper drags and hold smoke in your lungs for longer. As a result, you can end up with three to five times more tar and carbon monoxide in your body.

Pot smoke contains 50 to 70 percent more carcinogens than tobacco products. This is the reason why, as a long-term weed user, you’re just as likely as your tobacco-smoking counterpart to experience chronic cough and a higher risk of respiratory illness and infection.12

4. Stomach Health

Weed also causes severe stomach pain, vomiting, and nausea

Most weed users will complain of severe stomach pain, vomiting, and nausea. Heavy use has recently been identified as a cause for such symptoms, which no medical treatment can seem to alleviate. Smokers often resort to spending a considerable amount of time, even hours, in a hot bath or shower to relieve this.13

With the escalating rate of weed abuse, a medical condition known as Cannabinoid Hyperemesis Syndrome has also reared its head. This condition is characterized by chronic marijuana abuse, cyclic episodes of nausea and vomiting, as well as frequent hot bathing. However, information on the mechanism and its natural course is limited and requires further investigation.14

Effects Of Weed On Pregnant Women

Marijuana use is related to pre-term deivery

Expectant mothers are especially prone to the ill-effects of smoking pot. One study found that women who used weed during pregnancy were five times more likely to deliver babies with features akin to those found in fetal alcohol syndrome.15 Studies also show that marijuana use was related to pre-term delivery.16

When a breastfeeding mother uses weed, delta-9-tetrahydrocannabinol (THC) passes on to the baby through the milk. Infants exposed to THC experience increased tremors, poor sucking, slow weight gain, and poor feeding habits in the first month of life itself. Studies also suggest that the child could exhibit decreased motor skills at one year of age. For these reasons, the American Academy of Pediatrics recommends that women avoid breastfeeding if they’re heavy marijuana users.17 18 19

Can You Become Addicted To Weed?

When the user stops taking weed, they face mood swings, irritability, sleep trouble, wavering appetite, restlessness, and physical discomfort.

A person who uses weed regularly can develop marijuana use disorder or dependence. In fact, 9 percent of all users of marijuana become dependent on it.20 When the user stops taking weed, they face withdrawal symptoms, including mood swings, irritability, sleep trouble, wavering appetite, restlessness, and physical discomfort. They are also prone to fatigue, anger, aggression, and depression. This dependence may eventually become an addiction – where the person is unable to give up the habit and it takes over their life.21