When admitted in an emergency unit, young patients often present acute 
neurological effects of smoked marijuana. Other chronic adverse effects of 
marijuana are probably underestimated: postural syncope, arteritis, chronic 
bronchitis, amnesia. Marijuana may trigger a myocardial infarction and have a 
vasospastic effect. Marijuana has impairing effects on driving ability. Smoked 
marijuana is a potential respiratory tract carcinogen.