ASTHMA is CAUSED by: a widespread,
reversible, inflammatory condition of the lung's airways
resulting in narrowing. To grasp this asthma information we
need to take a microscopic look at your lungs.
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Your lungs are like an upside down tree.
In fact, you can feel the trunk in the front of your neck as
part of the Adam's apple. The trunk divides over and over again
like branches and twigs behind your breast bone. The leaves
at the ends are where air swirls and gases exchange with your
blood.
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One important difference however,
is that this 'tree' is hollow. When you
breathe you suck air through the trunk, past the divisions, and ultimately
to the 'leaves', or alveoli, where your blood takes up the oxygen
it needs and gets rid of carbon dioxide it made from burning your
food.
An asthma attack is when
the branches and twigs of the lungs narrow. That narrowing
is like the difference between blowing through a pipe (1) or
a straw (2). Not only is blowing through the straw noisy
i.e. wheezing, but it's also more difficult i.e. you feel short
of breath.
The reason your airways narrow in asthma
is because of inflammation. You already know what inflammation
is if you've ever been bitten by a mosquito. The bitten area
reacts to the irritant mosquito saliva by swelling, itching, and
reddening. A similar thing happens when you breathe in something
your lungs find irritating. The lining of the airways swell, minuscule
muscles in the airways contract clamping down the size of its
branch - preventing more coming in - mucous making is stepped
up to help wash it back out, and white blood cells come to
the area to destroy the substance. The end result is a narrowed, noisy
airway. But unlike the mosquito bite which only affects one area of
your skin, when you breathe in something it gets spread to all
of your airways so all are affected. That's what makes asthma
so dangerous; with all of your airways suddenly trickling air to the
'leaves' you find yourself suffocating. This is called an 'Asthma
Attack'.
The irritants which cause these
events can vary from colds, allergies, perfumes,
and many more as we'll see later under Types of Asthma.
