Air pressure is lower in the mountains. The air inside your ears takes
a while to adjust to pressure changes, and unequal pressure can cause
discomfort in the ears both when ascending and descending. This can be
particularly painful if you have nasal congestion or any condition
that blocks the eustachian tubes.
"When we are on the ground, say, at sea level or below, a maximum
amount of air presses down on us -- the whole weight of the atmosphere
above. But higher up, air gets thinner and thinner. So air pressure is
lower on top of a mountain or around a high-flying plane than in the
middle of New York's Times Square.
Although a passenger jet may fly 35,000 feet above the Earth, where
air is very thin, cabin pressure is kept higher, so that passengers
can breathe easily. Even so, as a jet climbs into the sky, air
pressure inside changes from that at ground level to that found on a
5,000-foot mountain. In a car climbing a real mountain, it's the same
story -- a dramatic change for the ears... When you drive up a
mountain or ascend in a plane, the air pressure in your ear canal
drops. Meanwhile, the air caught in your middle ear expands, making
your eardrum push out into the canal...
Descending to lower altitudes, it's the opposite story: The eardrum
caves in as outside pressure rises, with middle-ear pressure
temporarily stuck at 'cloud' or 'mountaintop' level. Now air rushes in
through the eustachian tube to fix the too-low pressure."
Milwaukee Journal Sentinel: Ears feel the pressure of change
"The outside of the eardrum is exposed to the pressure of the air
where ever you may be located. That pressure is 14.7 pounds per square
inch at sea level on a standard day.
The space inside of the eardrum is usually at the same pressure as the
outside. This is facilitated by a tube, one end of which opens into
the space of the 'inner ear' and the other end opens into the rear
part of your throat. But, that end of the tube is normally lightly
squeezed closed. Each time you swallow or yawn it opens just enough to
admit air to the inner ear, thereby equalizing the pressure with the
outside. Your ear drum then feels comfortable.
When you climb higher as in an airplane or in a car in the mountains,
you are going into an area of lesser air pressure. The air from the
lower altitude is 'trapped' in the inner ear. If it can not escape you
will soon have an ear ache caused by the ear drum being balooned
outward (stressed) by the higher pressure inside. So, it pushes out
through the 'eustachian tube' into your throat with bubble-popping
Physlink: Why your ears pop when you are riding on an airplane?
"Normally, the eustachian tube, a passageway that leads from the
middle ear to the back of the throat behind the nose, equalizes the
air pressure in the middle ear to the outside air pressure by opening
and letting air reach the middle ear. When your ears 'pop' while
yawning or swallowing, your eustachian tubes are adjusting the air
pressure in your middle ears...
Whether you're flying, scuba diving, climbing a mountain, or even
riding in an elevator, air pressure decreases as you go higher and
increases as you go lower. If the pressure isn't equalized, the higher
air pressure pushes on one side of the eardrum and causes pain."
Kids Health: Flying and Your Child's Ears
A condition of discomfort in the ear caused by pressure differences
between the inside and the outside of the eardrum... The air pressure
in the middle ear is usually the same as the air pressure outside of
the body. The eustachian tube is a connection between the middle ear
and the back of the nose and upper throat. Swallowing or yawning opens
the eustachian tube and allows air to flow into or out of the middle
ear, equalizing the air pressure on both sides of the eardrum. If the
eustachian tube is blocked, the air pressure in the middle ear is
different than the pressure on the outside of the eardrum, causing
Many people experience barotrauma at some time. Barotrauma commonly
occurs with altitude changes, such as with flying, scuba diving, or
driving in the mountains. If you have a congested nose from allergies,
colds, or upper respiratory infection, barotrauma is more likely."
ADAM Healthcare Center: Ear barotrauma
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