Insulin is a hormone that is responsible for allowing glucose in the blood to enter cells, providing them with the energy to function. A lack of effective insulin plays a key role in the development of diabetes.

Hormones are chemical messengers that instruct certain cells or tissues to act in a certain way that supports a particular function in the body.

Insulin is essential for staying alive.

In this article, we look at how the body produces insulin and what happens when not enough of it circulates, as well as the different types that a person can use to supplement insulin.

In some people, the immune system attacks the islets, and they cease to produce insulin or do not produce enough.

When this occurs, blood glucose stays in the blood and cells cannot absorb them to convert the sugars into energy.

This is the onset of type 1 diabetes, and a person with this version of diabetes will need regular shots of insulin to survive.

In some people, especially those who are overweight, obese, or inactive, insulin is not effective in transporting glucose into the cells and unable to fulfill its actions. The inability of insulin to exert its effect on tissues is called insulin resistance.

Type 2 diabetes will develop when the islets cannot produce enough insulin to overcome insulin resistance.

Since the early 20th century, doctors have been able to isolate insulin and provide it in an injectable form to supplement the hormone for people who cannot produce it themselves or have increased insulin resistance.

Learn about the discovery of insulin here.

A person can take of insulin based on how long they need the effects of the supplementary hormone to last.

Different types of insulin have different effects on blood glucose.

People categorize these types based on several different factors:

People most often deliver insulin into the subcutaneous tissue, or the fatty tissue located near the surface of the skin.

Three main groups of insulin are available.

Fast-acting insulin

The body absorbs this type into the bloodstream from the subcutaneous tissue extremely quickly.

People use fast-acting insulin to correct hyperglycemia, or high blood sugar, as well as control blood sugar spikes after eating.

This type includes:

Intermediate-acting insulin

This type enters the bloodstream at a slower rate but has a longer-lasting effect. It is most effective at managing blood sugar overnight, as well as between meals.

Options for intermediate-acting insulin include:

Long-acting insulin

While long-acting insulin is slow to reach the bloodstream and has a relatively low peak, it has a stabilizing "plateau" effect on blood sugar that can last for most of the day.

It is useful overnight, between meals, and during fasts.

Long-acting insulin analogs are the only available type, and these have an onset of between 1.5 and 2 hours. While different brands have different durations, they range between 12 and 24 hours in total.

Learn more about diabetes treatment by clicking here.