How Does Smoking Weed Affect My COPD?

Dear Dr. Mahler:

I am 67 years old and was diagnosed with “moderate” COPD about 3 years ago. At the time, I reduced smoking cigarettes to 1/2 pack each day, but now smoke weed several times a day to deal with family and financial problems. Weed really takes the edge off my “nerves.” Overall, I am doing reasonably well although I don’t exercise much, especially during the winter months. I like to play card games with my grandchildren, but can’t play games in the yard because of my breathing and arthritis.

At a recent check-up, my doctor said that my breathing tests are lower due to continued smoking and advised me to quit both cigarettes and weed. I know more about the bad effects of cigarettes, but find that weed really helps me feel halfway decent. I want to know how does weed affect my COPD.

Thanks.

Bill from Topeka, Kansas

Marijuana being rolled into a joint

Dear Bill:

Here is some basic information about weed that you may or may not know.

Weed, pot, and dope are names for marijuana that has mind-altering effects (psychoactive). Cannabis is a word that refers to all products derived from the Cannabis sativa plant. This includes its dried flowers, leaves, stems and seeds. The plant contains over 500 chemical substances including tetrahydrocannabinol (THC) and cannabidiol (CBD). THC is the chemical that causes mind-altering effects that makes you feel “high” and relieves stress.

forms of Cannabis sativa plant

Marijuana is usually smoked as a cigarette (called a joint) or in a pipe or bong and can also be mixed with foods or brewed as a tea. When marijuana is smoked, the active ingredient THC passes from the lungs, into the bloodstream and travels throughout the body including the brain. In the brain, THC connects to specific sites called cannabinoid receptors on nerve cells and influences the activity of those cells. Many of these receptors are found in the parts of the brain that influence pleasure, memory, thought, concentration, time perception, and coordinated movements.

How Does Smoking Weed Affect The Lungs?

Studies show that daily use of marijuana use is associated with an increase of asthma and COPD (https://pubmed.ncbi.nlm.nih.gov/40906010/) and increases the risk of cough, coughing up mucus, wheezing, and shortness of breath. Chronic bronchitis can develop with regular cannabis use.

Lower right image shows green mucus inside a breathing tube as found in chronic bronchitis

In a recent study from France, Dr. Pradere and colleagues showed that smoking both cigarettes and marijuana contributes to a higher incidencd fo emphysema and aggressive lung cancers (https://pubmed.ncbi.nlm.nih.gov/41005696/).

Bill - inhaling any toxic substance (tobacco, marijuana, smoke from firepace or firepit, air pollution, etc.) can aggravate your breathing tubes (bronchi) and cause inflammation. As you have COPD, I advise you to stop smoking both cigarettes and weed.

I advise patients in may practice who smoke weed to consider switching to edibles with THC. Unlike smoking, cannabis edibles may take hours to digest, and their effects may peak two to three hours after consumption and persist for around six hours. The food or drink used may affect both the timing and potency.

To start, you may want to try a low dose of a THC infused edible and then adjust the dose at the next time based on your experience.

Please note, the advice provided is not a substitute for asking your health care professional about your specific situation.

Sincerely,

Donald A. Mahler, M.D.