Overview

What is type 1 diabetes? A Mayo Clinic expert explains

Learn more about type 1 diabetes from endocrinologist Yogish Kudva, M.B.B.S.

I'm Dr. Yogish C. Kudva an endocrinologist at Mayo Clinic. In this video, we'll cover the basics of type 1 diabetes. What is it? Who gets it? The symptoms, diagnosis, and treatment. Whether you're looking for answers for yourself or someone you love. We are here to give you the best information available. Type 1 diabetes is a chronic condition that affects the insulin making cells of the pancreas. It's estimated that about 1.25 million Americans live with it. People with type 1 diabetes don't make enough insulin. An important hormone produced by the pancreas. Insulin allows your cells to store sugar or glucose and fat and produce energy. Unfortunately, there is no known cure. But treatment can prevent complications and also improve everyday life for patients with type 1 diabetes. Lots of people with type 1 diabetes live a full life. And the more we learn and develop treatment for the disorder, the better the outcome.

We don't know what exactly causes type 1 diabetes. We believe that it is an auto-immune disorder where the body mistakenly destroys insulin producing cells in the pancreas. Typically, the pancreas secretes insulin into the bloodstream. The insulin circulates, letting sugar enter your cells. This sugar or glucose, is the main source of energy for cells in the brain, muscle cells, and other tissues. However, once most insulin producing cells are destroyed, the pancreas can't produce enough insulin, meaning the glucose can't enter the cells, resulting in an excess of blood sugar floating in the bloodstream. This can cause life-threatening complications. And this condition is called diabetic ketoacidosis. Although we don't know what causes it, we do know certain factors can contribute to the onset of type 1 diabetes. Family history. Anyone with a parent or sibling with type 1 diabetes has a slightly increased risk of developing it. Genetics. The presence of certain genes can also indicate an increased risk. Geography. Type 1 diabetes becomes more common as you travel away from the equator. Age, although it can occur at any age there are two noticeable peaks. The first occurs in children between four and seven years of age and the second is between 10 and 14 years old.

Signs and symptoms of type 1 diabetes can appear rather suddenly, especially in children. They may include increased thirst, frequent urination, bed wetting in children who previously didn't wet the bed. Extreme hunger, unintended weight loss, fatigue and weakness, blurred vision, irritability, and other mood changes. If you or your child are experiencing any of these symptoms, you should talk to your doctor.

The best way to determine if you have type 1 diabetes is a blood test. There are different methods such as an A1C test, a random blood sugar test, or a fasting blood sugar test. They are all effective and your doctor can help determine what's appropriate for you. If you are diagnosed with diabetes, your doctor may order additional tests to check for antibodies that are common in type 1 diabetes in the test called C-peptide, which measures the amount of insulin produced when checked simultaneously with a fasting glucose. These tests can help distinguish between type 1 and type 2 diabetes when a diagnosis is uncertain.

If you have been diagnosed with type 1 diabetes, you may be wondering what treatment looks like. It could mean taking insulin, counting carbohydrates, fat protein, and monitoring your glucose frequently, eating healthy foods, and exercising regularly to maintain a healthy weight. Generally, those with type 1 diabetes will need lifelong insulin therapy. There are many different types of insulin and more are being developed that are more efficient. And what you may take may change. Again, your doctor will help you navigate what's right for you. A significant advance in treatment from the last several years has been the development and availability of continuous glucose monitoring and insulin pumps that automatically adjust insulin working with the continuous glucose monitor. This type of treatment is the best treatment at this time for type 1 diabetes. This is an exciting time for patients and for physicians that are keen to develop, prescribe such therapies. Surgery is another option. A successful pancreas transplant can erase the need for additional insulin. However, transplants aren't always available, not successful and the procedure can pose serious risks. Sometimes it may outweigh the dangers of diabetes itself. So transplants are often reserved for those with very difficult to manage conditions. A successful transplant can bring life transforming results. However, surgery is always a serious endeavor and requires ample research and concentration from you, your family, and your medical team.

The fact that we don't know what causes type 1 diabetes can be alarming. The fact that we don't have a cure for it even more so. But with the right doctor, medical team and treatment, type 1 diabetes can be managed. So those who live with it can get on living. If you would like to learn even more about type 1 diabetes, watch our other related videos or visit mayoclinic.org. We wish you well.

Type 1 diabetes, once known as juvenile diabetes or insulin-dependent diabetes, is a chronic condition. In this condition, the pancreas makes little or no insulin. Insulin is a hormone the body uses to allow sugar (glucose) to enter cells to produce energy.

Different factors, such as genetics and some viruses, may cause type 1 diabetes. Although type 1 diabetes usually appears during childhood or adolescence, it can develop in adults.

Even after a lot of research, type 1 diabetes has no cure. Treatment is directed toward managing the amount of sugar in the blood using insulin, diet and lifestyle to prevent complications.

Symptoms

Type 1 diabetes symptoms can appear suddenly and may include:

  • Feeling more thirsty than usual
  • Urinating a lot
  • Bed-wetting in children who have never wet the bed during the night
  • Feeling very hungry
  • Losing weight without trying
  • Feeling irritable or having other mood changes
  • Feeling tired and weak
  • Having blurry vision

When to see a doctor

Talk to your health care provider if you notice any of the above symptoms in you or your child.

Causes

The exact cause of type 1 diabetes is unknown. Usually, the body's own immune system — which normally fights harmful bacteria and viruses — destroys the insulin-producing (islet) cells in the pancreas. Other possible causes include:

  • Genetics
  • Exposure to viruses and other environmental factors

The role of insulin

Once a large number of islet cells are destroyed, the body will produce little or no insulin. Insulin is a hormone that comes from a gland behind and below the stomach (pancreas).

  • The pancreas puts insulin into the bloodstream.
  • Insulin travels through the body, allowing sugar to enter the cells.
  • Insulin lowers the amount of sugar in the bloodstream.
  • As the blood sugar level drops, the pancreas puts less insulin into the bloodstream.

The role of glucose

Glucose — a sugar — is a main source of energy for the cells that make up muscles and other tissues.

  • Glucose comes from two major sources: food and the liver.
  • Sugar is absorbed into the bloodstream, where it enters cells with the help of insulin.
  • The liver stores glucose in the form of glycogen.
  • When glucose levels are low, such as when you haven't eaten in a while, the liver breaks down the stored glycogen into glucose. This keeps glucose levels within a typical range.

In type 1 diabetes, there's no insulin to let glucose into the cells. Because of this, sugar builds up in the bloodstream. This can cause life-threatening complications.

Risk factors

Some factors that can raise your risk for type 1 diabetes include:

  • Family history. Anyone with a parent or sibling with type 1 diabetes has a slightly higher risk of developing the condition.
  • Genetics. Having certain genes increases the risk of developing type 1 diabetes.
  • Geography. The number of people who have type 1 diabetes tends to be higher as you travel away from the equator.
  • Age. Type 1 diabetes can appear at any age, but it appears at two noticeable peaks. The first peak occurs in children between 4 and 7 years old. The second is in children between 10 and 14 years old.

Complications

Over time, type 1 diabetes complications can affect major organs in the body. These organs include the heart, blood vessels, nerves, eyes and kidneys. Having a normal blood sugar level can lower the risk of many complications.

Diabetes complications can lead to disabilities or even threaten your life.

  • Heart and blood vessel disease. Diabetes increases the risk of some problems with the heart and blood vessels. These include coronary artery disease with chest pain (angina), heart attack, stroke, narrowing of the arteries (atherosclerosis) and high blood pressure.
  • Nerve damage (neuropathy). Too much sugar in the blood can injure the walls of the tiny blood vessels (capillaries) that feed the nerves. This is especially true in the legs. This can cause tingling, numbness, burning or pain. This usually begins at the tips of the toes or fingers and spreads upward. Poorly controlled blood sugar could cause you to lose all sense of feeling in the affected limbs over time.

    Damage to the nerves that affect the digestive system can cause problems with nausea, vomiting, diarrhea or constipation. For men, erectile dysfunction may be an issue.

  • Kidney damage (nephropathy). The kidneys have millions of tiny blood vessels that keep waste from entering the blood. Diabetes can damage this system. Severe damage can lead to kidney failure or end-stage kidney disease that can't be reversed. End-stage kidney disease needs to be treated with mechanical filtering of the kidneys (dialysis) or a kidney transplant.
  • Eye damage. Diabetes can damage the blood vessels in the retina (part of the eye that senses light) (diabetic retinopathy). This could cause blindness. Diabetes also increases the risk of other serious vision conditions, such as cataracts and glaucoma.
  • Foot damage. Nerve damage in the feet or poor blood flow to the feet increases the risk of some foot complications. Left untreated, cuts and blisters can become serious infections. These infections may need to be treated with toe, foot or leg removal (amputation).
  • Skin and mouth conditions. Diabetes may leave you more prone to infections of the skin and mouth. These include bacterial and fungal infections. Gum disease and dry mouth also are more likely.
  • Pregnancy complications. High blood sugar levels can be dangerous for both the parent and the baby. The risk of miscarriage, stillbirth and birth defects increases when diabetes isn't well-controlled. For the parent, diabetes increases the risk of diabetic ketoacidosis, diabetic eye problems (retinopathy), pregnancy-induced high blood pressure and preeclampsia.

Prevention

There's no known way to prevent type 1 diabetes. But researchers are working on preventing the disease or further damage of the islet cells in people who are newly diagnosed.

Ask your provider if you might be eligible for one of these clinical trials. It is important to carefully weigh the risks and benefits of any treatment available in a trial.

Sept. 15, 2023
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See also