What Happens If You Inhale Helium?

If you breathe too much helium, you might pass out

A girl blowing a balloon

Absodels / Getty Images 

Helium is a light, inert gas used for MRI machines, cryogenic research, "heliox" (a mixture of helium and oxygen), and helium balloons. You might have heard that inhaling helium can be dangerous, sometimes even fatal, but have you ever wondered how likely you are to harm your health breathing helium? Here's what you need to know.

Inhaling Helium from Balloons

If you inhale helium from a balloon, you get a squeaky voice. You might also get light-headed because you're breathing in pure helium gas rather than oxygen-containing air. This can lead to hypoxia or low oxygen. If you take more than a couple of breaths of helium gas, you could pass out, but unless you hit your head when you fall, you're unlikely to suffer any lasting harm. You might get a headache and a dry nasal passage. Helium is non-toxic and you'll start breathing normal air as soon as you move away from the balloon.

Breathing Helium From a Pressurized Tank

Inhaling helium from a pressurized gas tank, on the other hand, is extremely dangerous. Because the pressure of the gas is much greater than that of air, the helium could rush into your lungs, causing them to hemorrhage or burst. You'll wind up in the hospital or possibly the morgue. This phenomenon isn't exclusive to helium. Inhaling any pressurized gas can and probably will harm you. Do not attempt to breathe gas from a tank.

Other Ways of Inhaling Helium

It would be dangerous to put yourself into a giant helium balloon because you would deprive yourself of oxygen and wouldn't automatically start breathing normal air after you begin suffering the effects of hypoxia. If you see a giant balloon, resist any urge to try to get inside it.

Heliox is a mixture of helium and oxygen used for scuba diving and for medicine because it's easier for the lighter gas to pass through obstructed airways. Because heliox contains oxygen in addition to helium, this mixture does not cause oxygen starvation.

Test your knowledge of helium with a quick helium facts quiz.