You know the scene from movies or TV: some Nervous Nelly starts gulping for breath and is handed a paper bag to breathe into. The moment is usually played for laughs, the paper bag crinkling as it inflates and deflates. But hyperventilation is no laughing matter for those who experience it.

Hyperventilation is abnormally fast or deep breathing. It is also called "over-breathing." The boost in breathing can trigger a cascade of quickly emerging symptoms – a loss of carbon dioxide in the blood, a dip in blood pressure, tingling in the arms, lightheadedness, weakness, and even fainting.

The paper bag trick may or may not be the best quick fix, but the thing that the pop culture portrayals get right is the likeliest cause of hyperventilation. It often happens in moments of anxiety and nervousness. Confronted by a fear or phobia or in a fit of panic or anger, one may gasp for air and begin hyperventilating.

Some people frequently over-breathe and may have what is called hyperventilation syndrome and not even realize that they breathe quickly. Giveaways of hyperventilation syndrome include symptoms brought on by taking in too much air, such as belching, bloating, dizziness, or dry mouth. In other instances, hyperventilation can be an indication of an underlying condition, including congestive heart failure, heart attack, infections, and lung disorders.

Cope with the cause. To deal with stress-triggered hyperventilation, get to the root of the problem and explore ways to reduce tension and anxiety in your life. If other symptoms occur or if hyperventilation persists, consult your health care provider to determine whether underlying issues could be the cause of your symptoms.

React calmly to hyperventilation. If you begin to hyperventilate, you need to quickly raise your blood levels of carbon dioxide to stem the cascade of symptoms. Decrease your oxygen flow (thereby increasing your carbon dioxide level) by pursing your lips together to breathe or by covering your mouth so you breathe only through your nose. If you use a bag, it must be a paper bag – not a plastic one. Hold it over your nose and mouth and take 6 to 12 natural breaths. If you witness someone hyperventilating, offer reassuring words to calm them. Seek immediate medical attention if you experience rapid breathing for the first time or if you are in pain, have a fever, or are bleeding.