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Insulin therapy is often an important part of diabetes treatment. Understand the key role insulin plays in managing your blood sugar and the goals of insulin therapy. What you learn can help you prevent diabetes complications.

It may be easier to understand the importance of insulin therapy if you understand how insulin normally works in the body and what happens when you have diabetes.

The main job of insulin is to keep the level of sugar in the bloodstream within a normal range. After you eat, carbohydrates break down into sugar and enter the bloodstream in the form of glucose, a sugar that serves as a primary source of energy. Normally the pancreas responds by producing insulin, which allows sugar to enter the tissues.

Insulin also affects the liver. After you eat — when insulin levels are high — the liver stores extra sugar in the form of glycogen. Between meals — when insulin levels are low — the liver releases glycogen into the bloodstream in the form of sugar. This keeps blood sugar levels within a narrow range.

If your pancreas secretes little or no insulin (type 1 diabetes) or your body produces too little insulin or has become resistant to insulin's action (type 2 diabetes), the level of sugar in your bloodstream increases. Left untreated, high blood sugar can lead to complications such as blindness, nerve damage (neuropathy) and kidney damage.

If you have type 1 diabetes, insulin therapy replaces the insulin your body is unable to produce or use. Insulin therapy is sometimes needed for type 2 diabetes and gestational diabetes as well. If your doctor says that you need insulin therapy, take the recommendation seriously. Insulin therapy can help prevent diabetes complications by keeping your blood sugar within your target range.

To determine how much insulin you need and the most effective type of insulin therapy, your doctor will consider various factors — including the type of diabetes you have, how much your blood sugar fluctuates throughout the day and your lifestyle.

Insulin is usually injected, often several times a day. You may choose syringes, pens or an insulin pump. A new type of inhaled insulin (Exubera) can replace injections of short-acting insulin — but it doesn't replace longer acting insulin that may be required as part of your treatment plan. In fact, your doctor may prescribe a mixture of insulin types to keep your blood sugar in target range throughout the day.

Insulin therapy can be demanding, but it's important. By preventing diabetes complications, insulin therapy can help you lead an active, healthy life.