a type of sugar found in human blood; it's called glucose, and it
matters a lot how much of it you have circulating in your
bloodstream. It's harmful (though rare) to have too little of it; it's also harmful
(and common) to have too much of it. People who have too much of it
are said to be diabetic.
a little like gasoline. It's a high-energy, quick-burning fuel, it's valuable... and it's dangerous. You don't want
to run out of it, but neither do you want to leave a bunch of
it lying around just anywhere.
Glucose in the bloodstream is valuable, even essential (it's what keeps
your brain working, for one thing). The down side of having glucose
in your blood is that glucose is a sticky substance, and it attaches itself where it
isn't wanted. Specifically, it attaches itself to proteins all over your body. Over the long
term, this causes tissue damage.
Fortunately, the body is
able to repair the damage that glucose causes, replacing sugar-coated proteins
Unfortunately, the body can only repair damage which is happening at the normal, expected
rate. If your blood has more glucose in it than it ought
to, the damage is accelerated, and the body's repair processes can't keep up. Over time,
more and more protein throughout the body becomes encrusted with glucose, more tissue becomes damaged, and eventually a
lot of terrible medical problems develop.
To prevent this from happening, the body has a regulatory system which drives the glucose
level downward whenever it rises too high. Any failure of this regulatory mechanism causes some form
of diabetes, but because there's more than one way for the mechanism to fail, there's more
than one type of diabetes.
The regulatory mechanism
works by releasing a hormone called insulin. Insulin sends a message
to cells all over the body: start absorbing glucose immediately! The cells
glucose from the bloodstream, and convert it to a safe, stable form called
glycogen for storage (otherwise the glucose would simply harm the cells from
the inside instead of the outside, and nothing would be gained). Because the cells
pull in so much glucose from the bloodstream, the glucose level in the blood itself
drops back down to normal.
That's how it's supposed to
work, anyway. If you have Type 2 diabetes, your cells have become insensitive to
insulin, so they don't pick up the message to start absorbing glucose. Or
rather, they pick it up, but they don't respond to it adequately. They absorb
not as much as they ought to, so the glucose level builds up
in the bloodstream. This loss of sensitivity to insulin is usually called
"insulin resistance". The causes of it are not clear yet, but it is very
strongly associated with obesity and sedentary living. People who lose weight and start exercising usually
become sensitive to insulin again.
If you have Type 2, your top
priority should be to
insulin-sensitivity through exercise and weight loss. You should also moderate your intake of
foods which tend to elevate blood glucose. This approach is what will
get you the best results. A lot of people try to deal with the
disease just by taking diabetes drugs, without doing anything to change their health habits. These
people don't do so well.
Summing it up briefly
There's a widespread assumption that
people who have been diagnosed with Type 2 diabetes do not have enough patience,
intelligence, or curiosity to pay attention to a lengthy explanation of the
disease. You have to keep it simple or their minds wander.
I rather doubt this; my
guess is that most people who have been told they have a serious disease are
going to want to find out a lot more about it, even
if it takes up more than 20 minutes of their time.
However, I'm willing
to bow to convention, and take a stab at boiling the whole complicated subject
down to something brief. I hope that readers of this description will
understand that it leaves things out, things which are worth investigating. Please check out Diabetes Q&A if you would like to know more.