What are the possible side effects of taking cannabis?

THC cannabis does affect the short term memory, the more you smoke the more trouble you will have performing on a memory test and although it looks like a small memory deficit overtime and chronic use of cannabis can make it a significant memory deficit.
Cannabis tends not to interfere with problem solving or the ability to focus.
Since CBD Cannabis is supposed to be neuroprotective, a study of THC cannabis use balanced with high-dose CBD intake at another time in a 24 hour cycle could certainly reveal interesting information if the study was conducted to see how much the CBD protected the memory loss problem.


The main side effects that come to mind are:

  1. Loss of coordination (though some report certain strains can help coordination)
  2. Drowsiness
  3. Lack of motivation
  4. Difficulty concentrating
  5. Complications with your respiratory system (if smoking and even vaping)
  6. High blood pressure
  7. Anxiety (though certain strains can lower anxiety)
  8. Issues with short term memory
  9. Like with most substances that alter your mood state, a certain percentage of users will become addicted to cannabis. This is estimated to be about 9% of cannabis users by the NIDA

The side effects of cannabis are very real and should be paid appropriate attention. Some do claim that cannabis has no side effects and they are incorrect.


Are you talking about the side effects of THC? If so some of the side effects that people experience when they have taken too much THC for their system can be:
Rapid heart rate
Altered time perception
impaired motor coordination
delustional thinking
excessive sleepiness

If you or someone you know experiences these uncomfortable effects of too much THC, be reassured that you will be OK …According to Dr. Bonni Goldstein in her new book, there are no cannabinoid receptors in the area of the brain that control breathing and heart rate…that is why you cannot fatally overdose on cannabis…good news! Another tip if you feel you have taken too much THC is to drink cold lemonade, take calamus root, pine nuts or peppercorns…all of these natural foods contain chemicals that can alleviate the negative effects according to Dr. Ethan Russo…I am not a doctor but am putting this out there for educational purposes…


In addition to those answers below,
Cannabis intoxication can cause transient mood, anxiety, and psychotic symptoms. The relationship between cannabis use and long term risk of psychiatric disorders is less well understood. The association between cannabis use and psychotic disorders is possible in certain vulnerable populations of patients. Cannabis can unmask symptoms among individuals who have pre-existing vulnerability (such as a family history) to schizophrenia.


Additional more serious information regarding the side effects of cannabis:

  1. Cannabis has a risk for abuse and addiction. As I have predominantly dealt with teenagers and this problem in my career, I will share an example of this. If a patient uses high THC cannabis 4x/day for 7 months for instance, and then they decide to use cannabis only 1x/day, this patient would have the potential for withdrawal. The withdrawal symptoms will be exhibited as weight loss, nausea, paresthesia such as sensations of body tingling, and decreased motivation. This patient will want these symptoms to go away, and therefore will want to use cannabis to stop the withdrawal symptoms from happening (this is dependence), and therefore if you have dependence on a substance you are susceptible for addiction.

  2. Another side effect with using products with potent THC such as Dabs, can be syncope or passing out due to the sudden hit.

  3. Cannabinoid Hyperemesis Syndrome can also occur after years of daily use of cannabis. Symptoms occur with cyclical periods of nausea, vomiting and abdominal pain every 4-8 weeks. Patients tend to find relief with hot showers and symptoms will cease after stopping cannabis for 12 hours to 3 weeks on average.

  4. In pregnancy there is a correlation with cannabis use and low birth weights and developmental delays, but there is also a risk with breastfeeding. During breastfeeding studies show that 0.2% of THC crosses over into the breastmilk. One study found that if you use cannabis the 1st month of breastfeeding your child may have gross motor development delays by 1 year of age. Use with caution or at least avoid breastfeeding the 1st 3 months of life is recommended. I also want to advise that studies have shown that children who use cannabis before 25 years old, before the frontal lobe of your brain is developed, have lower IQ points.


The list of risks associated with cannabis is extensive as reflected by the previous responses. The average cannabis user should discuss their specific risks based on their own medical history with a knowledgeable health care provider. Some common ones I’d like to highlight are often overlooked and pertain mostly to middle aged and older individuals.

  1. Blood pressure changes – Cannabinoids and specifically THC have been associated with changes in blood pressure. Usually, there is a small increase in blood pressure that occurs transiently with use. Over time, cannabis products tend to lower blood pressure. Individuals on medications for high or low blood pressure should be aware of this effect and monitor their blood pressure regularly when using cannabis.
  2. Atrial fibrillation – small studies have shown that cannabis products can lead to changes in heart rhythm and trigger atrial fibrillation in some individuals. Anyone with a history of heart dysrhythmia should be aware of this side effect.
  3. Blood sugar changes – Cannabis products can stimulate appetite and lead to weight gain and poor blood sugar control in some diabetics.
  4. Instability – acute cannabis intoxication can lead to disorientation, which can lead to an increase risk of falls in those who use assistive devices to walk. Cannabis use should not be combined with other medications that can be disorienting such as short acting opiates or benzodiazepines.
  5. Anxiety/Panic attack – Overuse of THC-containing products in a single sitting or over time can worsen anxiety. Certain strains can also worsen anxiety for certain individuals. Acute cannabis intoxication can cause paranoia in some and is often caused by consuming too much THC-containing edible products. CBD-containing products and low THC concentration products tend to be better tolerated by those with a history of anxiety.
  6. Poor sleep – Cannabis overuse can disrupt REM-sleep leading to less restful sleep. Cannabis tends to be helpful for sleep for individuals who do not use it daily, use low doses, and maintain good sleep hygiene behaviors.


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