Although the public favors legalization and 60% of high school seniors do not think
that regular marijuana use is harmful, marijuana does have a plethora of adverse
short-term and long-term effects. Like nearly all use of drugs, self-medication is
not a good idea. Most of the effects of marijuana are caused by the impact on the
brain of the main active chemical in marijuana, THC (delta-9-tetrahydrocannabinol).
Older studies of the risk of marijuana may be less relevant because, through
selective plant breeding, the concentration of THC in marijuana has been increased
nearly three times compared to supplies that were available as recently as 1995.

Short-term effects of marijuana
When someone smokes or eats marijuana, THC enters the bloodstream and binds
with cannabinoid receptors in the brain. When these receptors are in the parts of the
brain that govern sensory perception and pleasure, it causes the marijuana “high.”
THC also binds with receptors in other parts of the brain that affect thinking, memory,
coordination, and concentration, and frequently causes unfavorable side effects,

• Difficulty with thinking and problem solving
• Problems with memory and learning, including problems studying, learning
new things, and recalling recent events. These problems can last for days
after use.
• Loss of coordination
• Distorted perception
• An increase in appetite
• Feeling lightheaded or drowsy
• A decrease in inhibitions that can lead to unsafe behavior such as risky sex
or driving or possibly a propensity for violence
• Hallucinations (when taken in high doses)
• Delusions (when taken in high doses)
• Psychosis (when taken in high doses)

Loss of coordination and distorted judgment and perception can make driving unsafe.
According to the National Institute on Drug Abuse (NIDA), studies in various
locations found that approximately 4% to 14% of drivers who sustained injury or
death in traffic accidents tested positive for THC. The NIDA also noted several
studies that found that marijuana use more than doubles a driver’s risk of being in
an accident. This can be compared to the overall risk of a vehicular accident that
increases by a factor of 5 with a blood alcohol level of 0.08%, the legal limit in most

A new danger from marijuana use has emerged when adulterated vaping apparatus
is used to inhale vaporized THC infused oils. The result has been multiple cases of
compromised respiration, with some users ending up on ventilators and some dying
from respiratory failure. It is still not entirely clear what has caused acute respiratory
failure after vaping, but the inhalation of oils causing lipid pneumonia is likely.

This blog presents opinions and ideas and is intended to provide helpful general information. I am not engaged in rendering advice or services to the individual reader. The ideas, procedures and suggestions in that are presented are not in any way a substitute for the advice and care of the reader’s own physician or other medical professional based on the reader’s own individual conditions, symptoms or concerns. If the reader needs personal medical, health, dietary, exercise or other assistance or advice the reader should consult a physician and/or other qualified health professionals. The author specifically disclaims all responsibility for any injury, damage or loss that the reader may incur as a direct or indirect consequence of following any directions or suggestions given in this blog or participating in any programs described in this blog or in the book, The Building Blocks of Health––How to Optimize Your Health with a Lifestyle Checklist (available in print or downloaded at Amazon, Apple, Barnes and Noble and elsewhere). Copyright 2021 by J. Joseph Speidel.