Biology - Other

Why do People Breathe

Erich Rosenberger M.D.'s image for:
"Why do People Breathe"
Image by: 

Why do people breathe? That's easy to answer - if you didn't breathe, you'd die in a few minutes. Try holding your breath for more than a minute or so and see what happens. You can't do it.

Okay, that's the snarky, sarcastic answer. But what is the real reason you breathe? There are a couple of major functions that are served by breathing. Let's take a look at them one at a time.


Breathing is how you get oxygen in to your body. Oxygen is a vitally important element that is essential for life. Your body uses oxygen in a series of chemical reactions that break down food to gain energy. Without oxygen, these chemical reactions could not take place, and all that potential energy would remain locked up in the food you eat. You would die shortly thereafter. 

Oxygen is brought in to the lungs and diffuses in to the bloodstream. It does this in tiny parts of the lungs called the alveoli. Once it's in the blood, the oxygen is taken around the body and distributed to tissues and cells as needed. Breathing is just the process that gets this entire cycle started.

Carbon Dioxide

One of the other primary functions of breathing is to get rid of carbon dioxide. Carbon dioxide is a waste product that is produced by the same metabolic processes that require oxygen to get started. At the end of the metabolic cycles that produce energy in your cells, there is an excess of carbon dioxide that must be eliminated from the body.

The waste carbon dioxide is transported to the lungs by your blood. It then diffuses in to the alveoli - just the opposite of the way oxygen gets in. When you exhale, the carbon dioxide is expelled in to the air around you. 

Maintaining acid/base balance in your blood

The last major function of breathing is related to maintaining the acid base balance in your blood. In order to function properly, your blood must remain at a very narrow range of acidity. If your blood becomes too acid or not acid enough (basic), there can be dangerous consequences. 

Carbon dioxide in the blood is slightly acidic. The precise chemistry is not important. If receptors in your body sense that your blood has become too acidic, it can make adjustments by increasing your breathing rate to get rid of the acidic carbon dioxide and return the balance to normal. The opposite is also true - if the blood becomes too basic, your breathing will slow down to retain carbon dioxide and acidify the blood.

Those are some of the major reasons why you breathe. You need to get oxygen in, carbon dioxide out, and maintain a proper balance of acidity in your bloodstream.

More about this author: Erich Rosenberger M.D.

From Around the Web