Hundreds of chemicals stream from our bodies into the air every second. These chemicals release into the air easily as they have high vapor pressures, meaning they boil and turn into gases at room temperature. They give clues about who we are, and how healthy we are.

Since ancient Greek times, we’ve known that we smell differently when we are unwell. While we rely on blood analysis today, ancient Greek physicians used smell to diagnose maladies. If they took a whiff of your breath and described it as fetor hepaticus (meaning bad liver), it meant you could be headed for liver failure. How you smell sheds light on how healthy you are - Study Finds