All of us eat sugars and carbohydrates. Our bodies metabolize both sugars and carbohydrates as sugar. The first thing your body does with carbohydrates that you eat -- potatoes, rice, bread, crackers -- is convert them into sugar.
In normal people, the sugar whips into the bloodstream, headed on its way to the cells. Your pancreas produces a special hormone called insulin that is like a "passport" that permits the sugar to enter the cells.
The sugar molecule comes knocking at the door of one of your cells (having arrived via the bloodstream). The cell says, "Who is it?" And the molecule says, "Mr. Sugar." The cell slides open the peephole. "Show me your passport." The molecule says, "Uh, I left it at home ... the dog ate it ..." Your cell slams shut the peephole, and leaves the door locked.
The "passport" is insulin. It's produced by your pancreas.
If (1) there isn't any insulin in your bloodstream, or (2) there isn't enough insulin, or (3) your pancreas produces a "weak" type of insulin, then the sugar just stays in the bloodstream, circulating through the body in a willy-nilly fashion. And this is a bad thing.
"Type 1" diabetes is congenital, or can be caused by physical trauma (such as a car wreck) that damages the pancreas. It is sometimes referred to (this is a misnomer) as "juvenile diabetes." People with Type 1 (only about 20% of all diabetics) have to monitor their blood sugar several times a day, and have to inject themselves with insulin regularly. If they don't, they can die in a matter of hours.
Folks with "Type 2" diabetes -- the other 80% of diabetics -- are not living on the brink of death each day. Most of them check their blood sugar only once per day.
What's wrong with having blood that's a little bit too sugary?
Well, on a short-term basis, it doesn't cause a problem. It's kind of like smoking: one cigarette won't kill you. Ten cigarettes won't kill you. With Type 2's, their blood sugar never gets so high (or low) that it represents an immediate threat to life. It takes a long time for the really harmful effects to show up.
Your blood sugar "count" (milligrams per deciliter of blood) should be between 70 and 140. If it goes much lower than 70, you are hypoglycemic, and you could become disoriented, go into a coma, even die. If your "count" goes up past 400, you could also become disoriented and go into a coma .... and die. The symptoms of low blood sugar are very much like the symptoms of high blood sugar.
That's why Type 1 diabetics often carry (1) insulin and (2) a cellophane package of cake frosting, so that they can take care of hypoglycemia and hyperglycemia. No kidding.
You can live with a blood sugar level of, say, 275 for quite a while without suffering any serious health problems. You'll find yourself having to urinate about every 90 minutes (you'll be getting up a lot during the night to go to the bathroom, and on a long drive, you'll be stopping at lots of gas stations). You'll be thirsty all the time. The word "diabetes" comes from two Greek words that mean "it sucks water." You see, your body treats the excess sugar in your bloodstream as a poison, and draws water out of your tissues in an attempt to flush out the "poison." Thus, you are thirsty all the time, and you have to urinate frequently.
Basically, you acquire Type 2 when you (1) get past the age of 40, (2) gain a lot of weight, and (3) have a family history of diabetes.
What are the possible consequences of leaving diabetes untreated for a long period of time? Well, you can end up having your feet amputated. And 20% of all the people who go blind each year do so as a result of diabetes. In other words, sixty-five times a day, every day (including today), someone goes blind because of problems with his blood sugar. And it can cause impotence in men. You can get rashes (especially on your feet and ankles) that just never heal. You can get lesions in odd places, and they scab over but never heal.
But the first symptom of high blood sugar is irritability. There are people who are impossible to live with only because their blood sugar is out of control. Do you find yourself angry over minor irritations, and you just can't stop being angry?
If you suspect that you have diabetes, you should go see your doctor.
For treatment, your doctor will give you instructions about how to eat and what to eat (it's not a diet, it's a meal plan); he'll tell you to get regular exercise; and he'll prescribe one or more drugs (the Big Three are glucophage, glucotrol, and avandia).