Side Effects of Cannabis: Why the Grass is not Always Green

Written by Review Weed Cannabis & Health Enthusiast
Updated: 2023-08-10
Adverse effects of marijuana

Table of Contents

Cannabis, ganja, pot, weed, marijuana – these different names for the same plant, which is now decriminalised in Thailand. Many people consume cannabis recreationally, but a growing number use it for their medical conditions and symptoms – often with a doctor’s prescription. Whatever may be the case, it is essential to be aware of the side effects of cannabis.

How does marijuana interact with the body?

Cannabis has several compounds known as cannabinoids which interact with the body and mind. Of these, only two are of interest to us: THC (tetrahydrocannabinol) and CBD (cannabidiol).

THC is a psychoactive, high-causing compound that causes you to laugh, get anxious, cry, eat, and party hard. CBD is the chill counterpart of THC; it does not get you stoned or buzzed but delivers the goodness of cannabis.

When you smoke or eat marijuana, THC passes through your bloodstream to reach your brain and the body. It then targets specific receptors and ‘takes over’ them temporarily, thus causing you to feel stoned. Since the brain has a fair number of these receptors, consuming weed gives you the head high that comes with the effects listed below.

Short-term effects of cannabis

Immediately after smoking weed, you will quite likely feel some (or all) of these effects:

  • Impaired memory, lack of concentration
  • Impaired body movement
  • Poor hand-eye coordination
  • Altered time perception
  • Increased sensitivity; you may see brighter colours or hear louder sounds
  • Increased heart rate
  • Sleepiness
  • Insomnia
  • Increased paranoia, anxiety, fear, panic 
  • Low reaction/response time
  • Hallucinations and delusions (when taken in high doses)
  • Head rush; mind running free with multiple thoughts and ideas
  • Couch lock sensation where you cannot move
  • Dry mouth
  • Nausea
  • Headache

It is worth noting that these effects and their intensities vary from person to person and depend on factors like age, BMI, tolerance, experience with other drugs, and so on. For example, a newcomer may be highly paranoid, while a seasoned user may ride that wave.

These effects will fade with time, usually within a couple of hours of smoking the weed. However, if you have taken edibles, then the effects may last up to eight hours.

Note: Smoking & eating cannabis will cause different experiences. Edibles take time to kick in, and since they are ingested, they are first broken down by your stomach and then metabolised by your liver. Then the THC reaches your bloodstream and the brain. As a result, it stays in your system for a long time.

The way you consume weed obviously makes a huge difference here; in this regard, cannabis oil is an excellent alternative to avoiding many of the side effects mentioned above as it does not contain THC and is non-psychoactive.

A chart depicting short term and long term side effects of cannabis.
Side effects of marijuana – what to expect for a few hours vs. long term

Long-term effects of cannabis

The long-term effects of marijuana are something that scientists are still researching. But, broadly speaking, they take time to develop and occur only after chronic, regular use of weed for days, weeks, months, and even years.

In short, if you have been smoking weed consistently for a really long time, you may experience:

  • Poor memory
  • Low concentration
  • A potential drop in IQ points (especially if you start smoking in your teenage years)
  • Antisocial behaviour
  • Potential for addiction

The negative effects of weed are more concentrated around its long-term use. Some of those are mentioned below.

Brain development issues

The human brain does not finish developing until the age of 25. Therefore, feeding cannabis to a brain under construction can impact mental abilities and even alter the brain structure. Areas of the brain involved in decision-making, memory retention, concentration, behaviour, and problem-solving may be impacted by chronic marijuana use starting from the teenage years.

Increased risk of psychosis

Those suffering from mental disorders and psychosis may find their condition worsened by cannabis. However, it does not mean that smoking weed will make you schizophrenic or put you at risk of psychosis.

It merely implies that if you have a family history of mental illnesses, you are encouraged to avoid weed as it may trigger the symptoms of these conditions. After all, weed is known to make you paranoid, anxious, and scared – adding these to the mix of already pre-existing conditions may not seem like a bright idea.

Risk of cardiovascular

One of the common effects of weed is that it causes the heart to pump blood faster, thus increasing your heartbeat.

This may not seem like a problem for healthy users, but if you already are at risk for heart problems or cardiovascular conditions, then your chances of incurring a heart attack are quite high in the hour after you smoke weed.

Lung problems

Cannabis or tobacco smoking is harmful to your health, period. Depending on how you are smoking weed – with tobacco or just pure grass – you will consume carcinogens which can irritate your lungs and cause breathing problems.

Conditions like chronic bronchitis, persistent cough with mucus, and lung infections may become prominent in heavy smokers.

Potential to make life better

A lot of people still spread the taboo that marijuana is bad. But truth be told, it can improve lives when consumed responsibly. CBD – the non-high compound of the plant – has many therapeutic benefits ranging from pain relief and anti-inflammatory properties to easing sleep problems, mental stress, and even patients suffering from cancer or epilepsy and seizures.

Hence, being aware of the side effects can help people enjoy the plant more responsibly. Therefore, young adults and teenagers should look to avoid it. At the same time, those seeking cannabis for their health conditions may want to consult with their doctor beforehand.