The Health Effects Of Marijuana You Need To Know

Marijuana is the most illicit drug used across the United States with over 19.8 million takers.1 And the most commonly used among young people across the world 2,  raking in over 10 billion U.S dollars in 2018.3

While there are many reasons for taking cannabis, there are numerous significant mental and body health effects to consider.


Current surveys suggest that up to 30 percent of all takers of marijuana end up having varying levels of dependency.4 This can have various effects on the body and mind. The following are some of the symptoms of one who has marijuana use disorder:

  1. Reduction in recreational or physical activities
  2. Constant dependency on cannabis to relax or function
  3. Basing friendship choices on the ability to get high
  4. Tolerance towards highness
  5. The crave for more dosage
  6. Unable to stop using or reducing5
  7. Learning problem and memory loss
  8. Thinking challenges
  9. Constant mucus filled coughs
  10. Anxiety or paranoia
  11. Loss of control
  12. Much hunger, and many more.6

THC (delta-9 tetrahydrocannabinol) is the primary contributor of marijuana potency or strength, and the reason takers become addicted. Since 2oo5 researches have pointed out that THC is on a significant rise against CBD (cannabidiol) the primary contributor of the medicinal properties of marijuana.7

Researchers are yet to ascertain the impact of high THC potency to the brain of takers and newbies. Since 2014 some samples of confiscated marijuana have shown to have a rising 80 percent of THC compared to a decade before.4

Some research suggests that the ability for one to become marijuana dependent also rests on gene.8 other contributing factors include self-control, availability of options that makes one feel good, and how plugged-in the taker is in the society, work, and family. Those that are much busy and more social tend to have more control.9

Being an addict is tough. Going through the withdrawal phase after long-term addiction is also tough and most times leads the affected back into the habit. The following are likable effects that a long-term cannabis addict experiences during the drug withdrawal phase:

  • Sleeplessness
  • Strong drug craving
  • Anxiety
  • Irritability
  • Decreased appetite.6


Marijuana affects the brain. This is why THC can provide the High takers are after. THC, being the most active ingredient of the plant, from the lungs enters the bloodstream and finds its way to the brain and is received by some elements and areas of the brain known as cannabidiol receptors.6

The cannabidiol receptor is part of the endocannabinoid system― all neurons, chemicals and other elements that are affected by Cannabinoids. Some of the areas of the brain have more cannabis receptors than others. The following are some of those parts, their functions and the effect of cannabis on them:

  • Amygdala― deals with emotions― leads to paranoia and panic.
  • Brain stem― information between the spinal column and the brain ― leads to antinausea effects.
  • Hippocampus― deals with learning new things― leads to impaired memory
  • Neocortex― complex thinking, movements, and feelings― altered thinking, feelings, and judgment.
  • Nucleus accumbens― reward and motivation― make the user feel good. 10

The effects of marijuana on the brain can be long-term or short-term. In the short-term, the individual experiences any of the above reactions aside from feeling high due to the overactivation of the brain cells done by THC.

So far, scientists have been unable to witness a decline in IQ level for heavy marijuana takers who started when they were adults. However, some studies reveal that teens who began smoking young and developed an ongoing disorder lost an average of 8 IQ points within 13 to 38 years of age.11

Currently, there has not been enough evidence to support that these losses can be regained or the effects are permanent even to those who stopped taking during adulthood.

The following are some of the long-term effects of marijuana on the brain:

  • Impairing brain development
  • Flaws thinking
  • Impair brain ability to learn
  • Poor memory
  • Affects how the brain builds connections for the areas affected.11


Marijuana contains some chemicals that are in tobacco. This allows it to affect the lungs and could also lead to cancer when smoked.12 The smoke of the cannabis also affects the large airways’ cell lining which irritates the throat and lungs amongst others.13 The following are some of the effects of marijuana and its smoke on the airways and lungs of firsthand users (individuals who use the drug):

  • Phlegm production
  • Wheezing
  • Chronic cough
  • Acute bronchitis 12
  • Airways inflammation
  • Lungs hyperinflation
  • Increased airway resistance 13

Studies have shown that the heavy smoking of marijuana leads to air pockets. These could appear between the lungs and the heart walls or both sides of the lungs. It could lead to further issues within the body like the decline of the immune system’s ability leading to high risk in sicknesses like pneumonia. 12, 13

When marijuana is burnt up for inhaling, it releases carcinogen properties into the taker. A high level of carcinogen combustion products like reactive oxygen species, phenols, nitrosamines, and vinyl chloride are administered into the body through smoking. As well, other cancer-causing substances like 50 percent of benzopyrene have been found in smoked marijuana.13

Secondhand marijuana smokers

Secondhand exposure to marijuana could have its risks. For people exposed to the drug in a well-ventilated space, the percentage of THC is way low to cause serious issues or fail driving tests.14

However, when sitting in a poorly ventilated area for a good while or inhaling the content in a confined space for close to an hour, the effects last longer and are way higher than in well-ventilated area. According to studies these people would be mildly high, have impaired movements, and a good percentage of THC in their urine and bloodstream.14

Due to the initial strict laws on cannabis, there are not enough studies on the effect of secondhand smoke exposure to people affected. However, based on peer reviews, and few studies carried out, here are some of the following health effects that secondhand smoke exposure leaves:

  • It impairs blood vessel functions
  • It administers cancer products to the body of the receiver.
  • One-minute exposure reduces the performance of endothelial functions for at least 90 minutes as against 30 minutes for tobacco. 15

The impairment of flow mediation dilation (the ability of arteries to expand in response to the increase in blood flow) for the femoral artery is also caused by being exposed to any kind of marijuana smoke. This test was done on marijuana products without THC and found to have the same effect for over 90 minutes.14


By taking marijuana users experience an increase in the rate of their heartbeat within 20 to 50 per minute. This effect could last from 20 minutes to three hours. Hence, studies suggest that the drug can impact heart functions and components. 16

While there are recent limited studies out there stating a three-fold risk of hypertension for the regulars, more recent studies have proven it wrong.16

Instead of increasing blood pressure, most recent researches with lesser limitations and more accuracy discovered that marijuana lowers blood pressure.16, 17

The same research has gone on to establish that cannabis is not responsible for the increase in heart attack and is responsible for the reduction in mortality due to atrial fibrillation.

The following are some of the known effects of marijuana on the heart:

  • Reduction in chances for coronary artery disease
  • Significantly low number of cardiac arrests among users.
  • Less mortality
  • Fewer atrial fibrillation occurrence among takers17

The legalization of marijuana in many parts of the world and the US opens a better chance for more findings. Current research linking marijuana to heart issues have only found a positive relationship. However, the long-term impact of the drug on the heart is not yet known.17


Marijuana, when taken in any other medium aside smoking, is not likely to cause cancer because all cannabinoids (the active chemical components of cannabis) including THC do not possess harmful constituents to bring about the condition.18

However, when burnt and inhaled as a smoke, researches have shown that the smoke contains the same carcinogen products that are in tobacco and houses some in a greater amount.13, 18

Though there are people recounting experiences that support cannabis aiding in the treatment or prevention of cancer, these experiences have not been scientifically proven. There is no substantial evidence to bring a conclusion to the role of cannabis regarding tumor cells in man. 19

The closest study that could suggest the cancer healing effects of marijuana was conducted on rats by administering a high dosage of cannabinoids to the subjects. It showed that these rats displayed protective effects against some kinds of cancer cells.19

On the other hand, though smoked marijuana contains high carcinogens, its role in causing cancer has not been proven. There are no results that hint to that.20,21

Old and extensive studies suggest that smoked marijuana does not seem to cause cancer though it possesses these carcinogens due to the effect of THC. Delta-9 THC is one of the primary active ingredients of cannabis and tends to kill aging cells which is against tumor cells’ survivor.21

Most recent researches suggest that the primary reason why the question: does marijuana cause cancer, is unanswered is because the likeability of those taken marijuana also taken tobacco is high. Hence, impaling research progress.20


Cannabinoids are now being used for medicinal benefits like pain relief in the health sector with the term medical marijuana or medical cannabis. However, there is yet to be an extensive study on it covering both the significant side effects as well as the positive effects to determine if the drug is better than other alternatives.22

Recent research conducted for non-cancer-causing chronic pains to determine the benefits of marijuana to prescribed users suggested that marijuana had no real effect in reducing the severity, interfering with the pain, preventing it or reducing the dosage when compared to other opioids used.23

A most recent study conducted on the different strains― compounds or types― of cannabis in relevance to their healing properties evaluated Cannabis Indica, Cannabis Sativa, and hybrids. From the study, participants indicated their preference for Indica in pain management, sleep, and sedation. They also preferred Sativa for energy and mood boost.24

The study further showed significant stats on pain reduction for participants who used Indica for the following kind of pain management:

  • Neuropathy
  • Joint pain
  • Spasticity
  • Non-migraine headache

Despite how insightful these reports are, the experiments were either small-scale or plagued with other limitations. Hence, there remains a need for further large and intense research conducted on marijuana regarding its effects on all kinds of pain.

Mental Health

Marijuana affects the mental health of those taking it. It could worsen the condition or risks of displaying symptoms of said condition depending on how young the taker is, how often it is taken, and the condition faced. 25

The following are some of the psychotic disorders that are influenced by marijuana:

  • Hearing voices
  • Depression
  • Paranoia
  • Anxiety
  • Psychosis
  • Substance use disorders. 25, 26

Why marijuana has been shown to influence worsening a mental condition, there has been no substantial evidence to it causing these conditions due to the varying factors:

  • Age of use
  • Genetic vulnerability
  • And dosage used. 26

Marijuana can bring chronic psychotic reactions in non-psychotic people when a certain high dosage is reached, and would only cease when the drug starts wearing off.26 When used by younger people, it could raise the risks of having mental challenges in the near future. 26, 25

These risks become more severe, and symptoms are likely to present themselves when the user has a gene or hereditary mental conditions as research has shown.26 Hence, marijuana can bring up temporary, long-term, and permanent mental challenges based on dosage, age, and gene.


Various researches conducted on pregnant women taking marijuana during their pregnancy period do not suggest any evident congenital disabilities for the child.27

Other human researches have revealed no connection with marijuana and the occurrence of miscarriages. However, those conducted on rats indicate that when taken in a very early stage of maternity could increase the risk. There is also 2.3 times rise in chances of stillbirth for women who use marijuana during this period. 28

While apparent effects of marijuana are lacking, several studies conducted on future developmental and hyperactive disorders has shown significant changes caused by the drug mostly on the brain.27, 28

The following are some of the negative impacts of marijuana on prenatal kids:

  • Impulsiveness
  • Inattention
  • Altered responses to visual engagements
  • High-pitched cries for babies
  • Increased trembling
  • Memory gaps
  • Gaps in problem-solving
  • And increased tendency to be a user as a young person. 27, 28

There is still the need for more research to distinguish the sole effects of marijuana from other environmental factors that could be at play during the moments of the mother’s use. 28

With concerns over low weight kids, mixed studies results are supporting or discrediting cannabis as a contributing factor. 29 However, for nursing mothers, a study has revealed that Delta-9 THC slips into the breast milk and increases in percentage based on how often and heavily the mother uses. 29

From prenatal to young adulthood, kids and teenagers possess developing brains. The younger they are, the greater the adverse and lasting effects of marijuana on their brains and functioning abilities thanks to THC. Hence, professionals and other health instrument recommend that both pregnant mothers and lactating mothers stay clear from the drug during these stages of their parenthood.28, 29



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