Understanding how insulin affects your blood sugar can help you better manage your condition. By Mayo Clinic Staff

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.

  • Regulate sugar in your bloodstream. 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.
  • Storage of excess glucose for energy. After you eat — when insulin levels are high — excess glucose is stored in the liver 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 doesn't produce enough insulin or has become resistant to insulin's action (type 2 diabetes), the level of sugar in your bloodstream increases because it's unable to enter cells. 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. Insulin therapy is sometimes needed for type 2 diabetes and gestational diabetes when other therapies have failed to keep blood glucose levels within the desired range. If your doctor says that you need insulin therapy, take the recommendation seriously. Insulin therapy can prevent diabetes complications by helping keep your blood sugar within your target range.

  • Type and amount of insulin. There are several types of insulin available that vary in how quickly and how long they can control blood sugar. Frequently your doctor may recommend more than one type of insulin. To determine which types of insulin you need and how much you need, your doctor will consider several factors. These include the type of diabetes you have, your glucose levels, how much your blood sugar fluctuates throughout the day and your lifestyle.
  • Insulin delivery options. Insulin is injected underneath your skin, often several times a day. You may choose among syringes, injection pens or an insulin pump that provides a continuous infusion of insulin through a catheter underneath your skin.

Insulin therapy can be demanding, but it doesn't have to dictate your life. By choosing a program that fits your needs and lifestyle, you can prevent diabetes complications and lead an active, healthy life.

Aug. 07, 2013