The good news about diabetes is that it can be well controlled with medications and diet. In the last decade, diabetes care has changed dramatically with the development of new drugs and devices. It’s now easier than ever to manage this chronic disease.

The bad news about diabetes is that many people who have the disease have not yet been diagnosed. Untreated and poorly treated diabetes is a major cause of blindness, impotence, kidney failure and heart disease.

Diabetes affects more than 18 million Americans, or about 8.7 percent of the adult population. For reasons that are not understood by researchers, more Hispanics, blacks and American Indians develop diabetes and kidney disease than do white Americans.

Our blood sugar levels are regulated by a hormone called insulin, which is produced by the pancreas, an organ next to the stomach. Diabetics have blood sugar levels that are too high. This happens because the pancreas produces little or no insulin, or the body does not respond to insulin normally.

Sugar – in the form of glucose – is present in most food we eat. When food is digested in the stomach and small intestine, this sugar is absorbed into the bloodstream. When blood sugar levels increase after a meal, this sends a signal to the pancreas to produce insulin. Insulin is pumped into the bloodstream, where its job is to carry sugar from the blood through the walls of blood vessels into the cells of all the body’s organs, muscles and other tissues. Our body’s cells get their energy from this sugar, and they need this fuel to function properly.

When insulin is not available, or if the body cannot use insulin properly, the amount of sugar in the blood rises, yet the cells of the body starve because sugar cannot cross from the blood to the cells. People with high blood sugar often feel weak and tired. They also feel thirsty because their body recognizes the need for water to dilute their too-sugary blood. They feel hungry because their body’s cells are not getting enough energy from the food they do eat.

About 10 percent of diabetics have Type 1 diabetes, also known as insulin-dependent or juvenile-onset diabetes. With Type 1 diabetes, an autoimmune disease, the pancreas stops making insulin entirely. This usually happens in children or young adults.

The other 90 percent of diabetics have Type 2 diabetes. Also known as non-insulin dependent or adult-onset diabetes, this type is increasingly being diagnosed in younger people, and is associated with obesity and family history. Type 2 diabetics still produce some insulin, but their bodies do not react to it normally.

Pre-diabetes is a newly recognized problem, in which people have elevated blood sugar levels due to insulin resistance, but not high enough for a diagnosis of diabetes. However, most people with pre-diabetes develop Type 2 diabetes within 10 years. Diet and exercise can really help at this stage: losing 5 to 10 percent of body weight and exercising 30 minutes a day can decrease your chances of developing Type 2 diabetes by 58 percent.

Gestational diabetes is diagnosed only in pregnant women. Obese women and those with a family history of diabetes are at highest risk. Also, Hispanics, American Indians, Pacific Islanders and blacks are at higher risk than whites. This condition goes away after pregnancy, but can indicate a future risk of Type 2 diabetes.

Diabetes is diagnosed by a simple blood test. Your blood is drawn after you have been fasting overnight, for 8 to 12 hours. A high fasting blood sugar level indicated diabetes.

Next week: learn about diabetes treatments and complications.

Kathryn B. Brown is a family nurse practitioner with a master’s degree in nursing from OHSU.