<s>[INST] My husband smokes marajuana, one joint per evening.  He had a pulmonary embolism this past summer and almost died.  He is now back to work, which is stressful, and the other evening he smoked marajuana again.  I am really concerned about this combination but would like to know what has truly been proven with this combination, rather than just confront him with "scare tactics".  Thanks. [/INST] Thanks for your question on Chat Doctor. I can understand your concern. Yes, smoking Marijuana will increase risk of recurrent pulmonary embolism. Actually any form of smoke is injurious to the body. Smoke causes inflammation and vasculitis. This vasculitis will produce thermogenic substances. These substances will damage already damaged pulmonary vessels and form thrombus and embolic. So chances of recurrent pulmonary embolism are more if your husband continues to smoke. So better to counsel him regarding this. You can enroll him in dead diction center where counselor is available for counseling. Hope I have solved your query. I will be happy to help you further. Wishing good health to your husband. Thanks. </s>