Barotrauma. It sounds like something an opera singer might have—but chances are good that you've experienced it yourself. Barotrauma refers to the uncomfortable pain in your ears when there is a sharp change in altitude, such as during flying, diving, mountain climbing, or even riding in an elevator. Usually it's just a temporary discomfort, but in certain instances it can result in ear damage.

What's happening in the ear?
Why do your ears "pop" when air pressure changes? The answer is found in the complex structure of your ear, and the way air pressure is balanced inside and outside your head.

The ear is made up of three main compartments: the outer ear, middle ear, and inner ear. Air enters the outer ear (the part that you can see) and travels through the ear canal to the eardrum. In between the eardrum and the entrance to the middle ear is an air pocket. This air pocket is connected to the Eustachian tube, which extends from the middle ear to the back of the nose. As you breathe, the Eustachian tube is constantly circulating air to the middle ear air pocket, which keeps air pressure inside and outside your head in equal balance. The "popping" feeling you may experience is due to the compression or expansion of air as you move up or down.

Why head colds are trouble:
Normally, a head cold is a minor health ailment. But if you're planning on flying or scuba diving, a head cold can become a significant problem. Head colds, allergies and sinus infections may block the flow of air through the Eustachian tube, creating a vacuum in the middle ear. This prevents air pressure equalization, and causes the eardrum to stretch, which is painful.

Divers need to be especially careful of air pressure equalization when ascending or descending. If the Eustachian tube is blocked, extreme changes in air pressure can force fluid (like blood serum) to seep into the middle ear to fill the vacuum as a diver ascends or descends. Divers have nicknamed this painful feeling "the squeeze" when it happens during descent (or "reverse squeeze" during ascent.) In addition, fast descent without proper equalization may rupture the eardrum.

The best advice on flying or diving when you have a head cold, allergies or sinus infection: Don't!

Prevention and treatment of barotrauma:
There are several ways to help prevent, or treat ear discomfort during altitude changes:

Prevention:
• Stimulate airflow: The key to preventing barotrauma is maintaining a good flow of air into the Eustachian tube. Here's how:
Sip fluids to keep swallowing.
Yawn frequently.
Chew gum or suck on candy.
• Stay awake during descent:Because you seldom swallow during sleep, the Eustachian tube may remain closed. Try to have someone wake you before the plane descends.

Treatment for discomfort:
Pinch your nostrils shut, close your mouth, and blow gently.
Yawn with your mouth closed.
When you hear a "pop", you will have succeeded in unblocking your ears.

Nearly all cases of barotrauma that occur during flying or mountain climbing resolve spontaneously without incident. However, divers who experience severe pain or significant hearing loss should see a doctor.

Flying with children:
You've probably noticed that infants and children often become fussy or agitated during plane take-offs and landings. In many cases this is due to ear pain. Small children are especially prone to blockage of their narrow Eustachian tubes.

The best way to help prevent barotrauma in children is to encourage them to drink liquids. Drinking keeps the Eustachian tubes clear by:

Thinning nasal secretions
Promoting swallowing

Try to breast- or bottle-feed infants during take-off and before descent. Also, be sure to have a pacifier for your infant to suck on. For older children, bring non-caffeinated drinks (water is best), or gum or hard candy. You may want to give older children acetaminophen a half hour before flying.

Medication do's and dont's:
Some frequent air travelers take decongestant pills or use nasal spray to prevent barotrauma. These medications help shrink membranes, and help the ear to equalize air pressure more easily. However, you should avoid these medications if you have the following:

Heart disease
Irregular heart rhythms
High blood pressure (hypertension)
Elevated thyroid hormone (hyperthyroidism)
Anxiety or excessive nervousness

Also, if you are scuba diving, do NOT take antihistamines, which may cause disorientation or drowsiness during diving.

Resources:

Scuba Diving Magazine

American Academy of Pediatrics