Diabetes mellitus: what kind of disease it is and what types exist

"Diabetes is when you eat too much sugar." That explanation sounds convincing until you learn what actually lies behind it: not candy, but the hormone insulin and how the body processes glucose. What follows is a general overview of the disease without scare tactics and without treatment regimens.

What diabetes mellitus is

Diabetes mellitus is a disease in which the level of glucose (sugar) in the blood is too high. Glucose is the main source of energy: the body produces some of it itself and gets some from food. The hormone insulin, which the pancreas produces, carries glucose from the blood into the cells.

In diabetes, the body does not produce insulin, or produces too little of it, or does not use it properly — or all of these at once. Glucose stays in the blood and does not reach the cells. The course is chronic: it affects not only carbohydrate metabolism but also fat, protein, mineral, and water-salt metabolism.

What types of diabetes exist

Type 1. There is little or no insulin: the immune system attacks and destroys the cells that produce it. It is often found in childhood, but it can develop at any age. It cannot be prevented.

Type 2. The most common form. Insulin is present, but cells respond poorly to it and take up glucose poorly. The risk is higher with obesity or excess body weight, age over 35, a family history of diabetes, prediabetes, previous gestational diabetes, lack of activity, high blood pressure, and polycystic ovary syndrome. Part of the risk is reduced by lifestyle changes.

Gestational. It occurs during pregnancy, when the body does not have enough additional insulin. It usually resolves after childbirth. Pregnant women are tested at 24–28 weeks. There are also rarer types.

Prediabetes and the development of the disease

Prediabetes, or non-diabetic hyperglycemia, is a condition in which blood glucose is above normal but not high enough to diagnose diabetes. People with prediabetes have a higher risk of developing type 2 diabetes, but it can be reduced by lifestyle changes.

Complications of diabetes develop over time and are associated with high blood glucose levels.

What happens to sugar in diabetes

Glucose accumulates in the blood because it does not get into the cells. This leads to typical manifestations:

• constant thirst;
• frequent urination, including at night;
• severe fatigue;
• weight loss without trying to lose weight;
• intense hunger, blurred vision, numbness or tingling in the feet and hands, poorly healing wounds.

In type 1, symptoms come on quickly and can be severe. In type 2, they build up over years, often mildly, so that the person does not notice them. In gestational diabetes, they are most often absent altogether. A person with diabetes may look normal: many have no complaints, which is why testing is also done for those who are simply at risk.

As long as blood glucose is below the kidney threshold (about 10 mmol/L), sugar is not found in the urine; above it, it appears there as well.

How diabetes is diagnosed

Diagnosis is based on blood glucose tests, one or several, including the A1C test. The doctor evaluates the numbers in conjunction with complaints and risk factors. If symptoms have appeared in you or your child, an appointment with a doctor is needed urgently, not "sometime."

What complications are possible and when a doctor is needed

Over time, high sugar damages blood vessels and nerves. The list includes: heart attack and stroke, kidney problems, nerve and foot damage (peripheral neuropathy), vision problems (adults and children from age 12 — eye screening once every 1–2 years), and gum disease. The more steadily sugar is kept at the target agreed with the doctor, the lower the chance of such consequences.

See a doctor for thirst, frequent urination, fatigue, unexplained weight loss, blurred vision, numbness in the limbs, and poorly healing wounds. And also for risks without any complaints at all.

Diabetes itself is not a reason to call an ambulance; 103/112 — for signs of a heart attack or stroke.

This text is for reference: it will help you understand what is what, but it does not replace a doctor's consultation — discuss the numbers and the diagnosis with an endocrinologist.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer