hyperventilation
Meaning of hyperventilation: Often blamed on nerves, but the same pattern is one of the earliest warnings of serious illness elsewhere in the body.
Definition of hyperventilation
Hyperventilation is breathing faster or deeper than the body's need for gas exchange requires, so carbon dioxide is blown off faster than it is produced. Blood carbon dioxide falls, the blood becomes more alkaline, and small blood vessels in the brain narrow. The result is lightheadedness, tingling around the mouth and in the fingers, chest tightness and a sense of not getting enough air.
Why does breathing too much cause tingling and dizziness?
Breathing sets how much carbon dioxide stays dissolved in the blood. Carbon dioxide forms an acid in water, so blowing off more than the body makes leaves the blood more alkaline than usual. That shift changes how calcium behaves in the blood and makes nerves fire more readily, which produces the familiar pins and needles around the mouth, in the fingers and in the toes, and sometimes a cramping spasm of the hands. At the same time the small arteries feeding the brain narrow, so blood flow through it drops, and lightheadedness, blurred vision and a sense of unreality follow. None of this comes from a shortage of oxygen. Oxygen levels are usually normal or high, which is exactly why the feeling of suffocating misleads so effectively.
What sets it off?
Panic and acute distress are the best known trigger and the one the word usually brings to mind. They are not the commonest cause in a hospital. Faster breathing is among the earliest responses to serious illness anywhere in the body, and it often appears before blood pressure or alertness changes, which is why an unexplained rise in breathing rate is treated as a finding needing an explanation.
| Cause | What drives the breathing |
|---|---|
| Panic or acute distress | Alarm signals overriding the automatic breathing rhythm |
| Acid building up in the blood | Carbon dioxide blown off to offset uncontrolled diabetes or kidney failure |
| Lung disease | Low oxygen and inflamed tissue, as in pneumonia or a clot in the lung |
| Severe infection or fever | Raised demand for oxygen and circulating inflammatory signals |
| Aspirin poisoning | Direct stimulation of the breathing center in the brainstem |
How does it differ from breathlessness?
Dyspnea is the sensation of not getting enough air and describes what a person feels. Hyperventilation describes what the breathing actually does, and it can be counted and measured. The two frequently travel together, which is why they get run into one, yet either occurs alone. Someone losing blood may breathe fast with no sense of struggle at all, while advanced emphysema brings overwhelming air hunger with breathing that is slow and labored rather than fast. Rebreathing into a paper bag was once a routine response and has fallen out of use, because it lowers oxygen and does harm when the fast breathing turns out to have a cause other than anxiety.
Also known as
Used in a sentence
Hyperventilation was noted on arrival, and the blood gas showed a low carbon dioxide level.
Good to know
Fast breathing is commonly attributed to anxiety, yet it is also among the earliest signs of severe infection, a clot in the lung and acid building up in the blood, and the oxygen level can read as normal in all of them.
Word origin
Where “hyperventilation” comes from
Hyper- is Greek for over or beyond, and ventilation comes from the Latin ventilare, meaning to fan or expose to the wind.