India, Sept. 25 -- You are what you eat - but have you ever thought about what you breathe? If you think swapping cigarettes for a vape pen or taking a casual puff at a party is harmless, a cardiologist has a reality check for you. Also read | Woman's vaping video from Bali shows 'inhaling 1 vape pod worse than smoking 12 cigarettes': Doctor reveals the truth

In a September 24 Instagram video, Dr Evan Levine, a New York-based cardiologist with over 30 years of experience, broke down the 'five most dangerous' things people voluntarily inhale. And your heart reacts within seconds. Counting down from least dangerous to most catastrophic, here's what actually happens to your heart and blood vessels.

Weed may feel mainstream, but 'natural' d...