Type 1 Diabetes

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What is type 1 diabetes?

About 1.25 million people in the United States have type 1 diabetes, according to the American Diabetes Association. The organization also estimates that 40,000 Americans a year learn they have the disease.

Type 1 diabetes used to be called juvenile diabetes or insulin-dependent diabetes. This reflected the fact that it is common in children and requires insulin treatment. However, those names aren’t entirely accurate because adults can get type 1 diabetes and people with type 2 diabetes can depend on insulin as well. Today, doctors recognize the two main types of diabetes—type 1 vs. type 2 diabetes—by how they develop.

Type 1 diabetes is the result of beta cell destruction in the pancreas. Beta cells make insulin, the hormone your cells need to turn sugar from food into energy. Without insulin, your body can’t use sugar for fuel. Instead, the sugar remains in the bloodstream causing high blood sugar, or hyperglycemia. Type 2 diabetes stems from a problem with normal insulin signaling that ultimately leads to insulin resistance.

The three main symptoms of hyperglycemia are excessive hunger, thirst and urination. Seek prompt medical attention if you have these symptoms or notice them in your child.


What are the symptoms of type 1 diabetes?

In type 1 diabetes, beta cell destruction can happen over months or years. However, once enough beta cells no longer function, symptoms can start quickly. They can become noticeable in a few weeks and tend to be severe.

Common symptoms of type 1 diabetes

The most common type 1 diabetes symptoms include:

Serious symptoms that might indicate a life-threatening condition

Sometimes, type 1 diabetes causes blood sugar to go so high that it becomes life threatening. This condition is ketoacidosis. Seek immediate medical care (call 911) if you, or someone you are with, have any of these life-threatening symptoms including:

Regular medical care throughout life can help identify early signs and symptoms of type 1 diabetes. Because symptoms often develop suddenly, it’s important to see your doctor when you first notice them. Your doctor can determine whether diabetes or some other condition is at the root of the problem.


What causes type 1 diabetes?

Doctors and researchers do not know for sure what exactly causes type 1 diabetes. It is most likely an autoimmune disease, meaning your immune system attacks your own cells as if they were foreign substances. In type 1 diabetes, your immune system targets and attacks the insulin-producing beta cells in the pancreas. Why this happens is less well understood. Most experts believe it is a combination of genetic and environmental factors. Some people may have genes that increase their risk of developing type 1 diabetes. It is also possible that some sort of trigger, such as a viral infection, ignites the autoimmune process.

Risk Factors

What are the risk factors for type 1 diabetes?

Currently, there is limited information about risk factors for type 1 diabetes. However, there are a few factors doctors know about that increase the risk of developing type 1 diabetes.

These risk factors include:

  • Age: You can get type 1 diabetes at any age, but it commonly develops during childhood, teenage years, and early adulthood.

  • Family history: People who have a parent or sibling with type 1 diabetes are more likely to develop the disease. This may be due to certain genes passing down in a family.

  • Geography: Type 1 diabetes tends to occur more frequently in northern climates, as you get farther away from the equator.

  • Race: In the United States, Caucasians tend to develop type 1 diabetes more often than other races.

Reducing your risk of type 1 diabetes

There is no known way to prevent or reduce your risk of type 1 diabetes. This reinforces the importance of seeing your doctor on a regular basis if you are at risk for the disease. If you need more information about your risk, talk with your doctor.


How is type 1 diabetes treated?

The goal of type 1 diabetes treatment is to normalize blood sugar levels. For most people, this means keeping blood sugar between 80 and 130 mg/dL. There are other targets, including after-meal blood sugar levels and HbA1c levels. HbA1c is a test that shows long-term blood sugar control over the last 2 to 3 months. In most cases, the goal result is 7%. Your doctor may have different target levels for you, depending on your specific situation.

To accomplish these goals, people with type 1 diabetes need to use insulin. There are different types of insulin based on how quickly and how long they work:

  • Rapid-acting insulin

  • Short-acting insulin

  • Intermediate-acting insulin

  • Long-acting insulin

Rapid- and short-acting insulins work to cover rises in blood sugar after meals. Intermediate- and long-acting insulins have a more gradual action to provide a basal level of insulin throughout the day.

The main ways to take insulin is by giving yourself injections throughout the day or using an insulin pump. People who use insulin injections use a needle and syringe to inject insulin under the skin. An insulin pump is a small device on the outside of your body that delivers insulin under your skin through a small catheter.

When you use insulin, you need to monitor your blood sugar throughout the day. These measurements help you fine-tune your insulin dose. It can also tell you if your blood sugar levels are getting too high or too low. There are two main ways to check your blood glucose—a glucometer or a continuous glucose monitor (CGM). With a glucometer, you prick your finger several times a day to check your blood sugar. A CGM has a sensor under your skin that checks your blood sugar every few minutes. Many people with type 1 diabetes use a CGM because it is especially helpful for preventing hypoglycemia—low blood sugar. It also shows you the rate and direction of your blood sugar levels.

CGM technology paired with an insulin pump is known as a hybrid closed-loop system, or artificial pancreas. The system monitors blood sugar and delivers basal insulin as necessary. However, it requires information from you about meals in order to deliver short-acting insulin doses. Someday, a fully closed-loop system may be available.

Other components of type 1 diabetes treatment include:

  • Carbohydrate counting and monitoring

  • Food planning including meals, snacks and desserts

  • Medications to manage other chronic conditions such as high blood pressure

  • Regular exercise and physical activity


What are the potential complications of type 1 diabetes?

There are several potential complications of type 1 diabetes and its treatment. One of the most common is hypoglycemia, which is when your blood sugar drops below your target range. There are three basic causes of hypoglycemia in type 1 diabetes:

  • Increased physical activity

  • Not enough food or carbohydrates

  • Too much insulin

Warning signs include:

If you have these symptoms, check your blood sugar. If your level is low, you need a quick source of sugar, such as glucose tablets. Other options include sugar, honey or fruit juice. Without adequate treatment, hypoglycemia can be life threatening. Seek immediate medical care (call 911) if someone with diabetes has low blood sugar symptoms that aren’t responding to treatment or if they have fainted or lost consciousness.

Other complications can develop if blood sugar levels remain uncontrolled above your target range. Chronically high blood sugar (hyperglycemia) damages nerves, blood vessels, and other tissues. This can result in heart disease, stroke, kidney damage, neuropathy, and eye, foot and skin problems. In women, it can cause pregnancy complications.

The best way to protect yourself and prevent diabetes complications is to follow your treatment plan closely.

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Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2018 Oct 9
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  10. Who’s at Risk? Centers for Disease Control and Prevention. https://www.cdc.gov/diabetes/basics/risk-factors.html

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