10. Smoking marijuana increases the risk of having a heart attack and testicular cancer.
Studies reported in Marijuana Use: Detrimental to Youth by the American College of Pediatricians indicate that individuals have nearly a five-times greater risk for heart attack within the first hour of smoking marijuana most likely because of its effects on increasing blood pressure and heart rate, and reducing the blood’s ability to carry oxygen. In addition, marijuana smoke, like tobacco smoke, is an irritant carrying toxic gases and particles that can result in chronic cough, respiratory infections, and bronchitis. Link: (Marijuana Use Detrimental to Youth)
Lastly, studies cited by NIDA show that marijuana use during adolescence increases risk for an aggressive form of testicular cancer. Link: (What are Marijuana's Effects on General Physical Health)