Drowning occurs when normal air exchange in the lungs is prevented. This can happen when a person's nose and mouth are under the surface of a liquid, or when a person's face comes in contact liquid.

Drowning is caused by breathing problems because of liquid, such as water. At first, the person will hold his or her breath. Eventually, the person will no longer be able to hold it. The liquid will flow into the lungs. This liquid will not allow the normal gas exchange in the lungs to happen.