What is Type 1 diabetes?

Type 1 diabetes¹, previously known as juvenile diabetes or insulin-dependent diabetes, is a chronic autoimmune disease in which the pancreas produces little or no insulin. Insulin is a hormone needed to allow sugar (glucose) to enter the body’s cells to produce energy.

Although type 1 diabetes is usually diagnosed during childhood or adolescence, it can also develop in adults. Different factors, including genetics and some viruses, can contribute to type 1 diabetes.

The causes of type 1 diabetes are not fully known, despite active research. There is currently no cure for the disease. Treatment focuses on managing blood sugar levels with insulin pumps or injections, diet, and healthy lifestyle choices.

How common is type 1 diabetes?

Approximately 1.25 million Americans² currently have type 1 diabetes, and an estimated 40,000 more are diagnosed with it each year.

According to Beyond Type 1³, there was a 21% increase in people under the age of 20 diagnosed with type 1 diabetes from 2001–2009. Furthermore, less than ⅓ of people with type 1 diabetes consistently achieve target blood glucose levels.

What is diabetes mellitus?

Diabetes mellitus⁴ is the clinical term for diabetes. It refers to a group of diseases that prevent the body from using glucose, or blood sugar, properly. This condition is more common than diabetes insipidus.

Diabetes is classified into two main types: type 1 and type 2.

Type 1 diabetes is the most common form of diabetes in people under 30 but can occur at any age. 10% of people with diabetes are diagnosed with type 1.

Type 2 diabetes⁵, also called adult-onset diabetes, occurs when the pancreas makes insulin, but the insulin produced is insufficient or doesn’t work properly.

Type 2 diabetes is usually controlled with healthy lifestyle choices. Sometimes, however, treatments can include oral glucose-lowering medications or insulin injections.

Type 2 diabetes occurs most often in people who are over 45 years old⁶ , but can occur even in childhood when one or more risk factors for developing the disease are present. Roughly 90% of people with diabetes have type 2.

What is diabetes insipidus?

Diabetes insipidus⁷ is an uncommon from of diabetes. It occurs when the body can’t regulate its fluid levels properly, causing an imbalance. This imbalance causes extreme thirst and the production of large amounts of urine.

What is gestational diabetes?

Gestational diabetes⁸ is a form of diabetes that develops during pregnancy (gestation), usually about halfway through term.

Like other types of diabetes, gestational diabetes affects the way the body uses blood sugar (glucose). It causes hyperglycemia (high blood sugar) and can affect both a woman’s pregnancy and the health of her baby.

By definition, gestational diabetes develops during pregnancy in women who did not already have diabetes beforehand. Some women, however, develop gestational diabetes during more than one pregnancy. Gestational diabetes is sometimes treated with insulin, but it can usually be managed by making healthy lifestyle choices, such as eating a healthy diet and getting sufficient exercise.

If a woman develops gestational diabetes, her blood sugar levels will likely return to normal shortly after giving birth. However, controlling blood sugar during pregnancy can help prevent birth complications and keep both the mother and her baby healthy.

Type 1 diabetes causes

The exact cause of type 1 diabetes is unknown. It is thought to be caused by a combination of genetic and environmental factors.

What is known is that in people with type 1 diabetes, the body’s immune system (which normally fights harmful bacteria and viruses) mistakenly attacks and destroys the pancreas’ insulin-producing cells (called islet cells).

After a significant number of islet cells are destroyed, the pancreas no longer produces sufficient insulin.

Glucose, a form of sugar, comes from two major sources: the food you eat and your liver. This sugar is the main source of energy for the cells that make up muscles and other tissues. Insulin helps glucose enter your cells after being absorbed into the bloodstream.

When the immune system attacks islet cells and leaves the body with little or no insulin, glucose builds up in the bloodstream instead of being transported into cells to be used as energy. This buildup of sugar can cause life-threatening complications.

Risk factors for type 1 diabetes

Some risk factors⁹ that may increase the chances of having type 1 diabetes include:

• Family history: People with a parent or sibling with type 1 diabetes have a slightly increased risk of developing the condition.
• Genetics: The presence of certain genes indicates an increased risk of developing type 1 diabetes.
• Geography: The incidence of type 1 diabetes tends to increase as you travel away from the equator.
• Age: While type 1 diabetes can occur at any age, its appearance is highest at two peaks: the first in children between 4–7 years old, and the second in children between 10–14 years old.

What is prediabetes?

Prediabetes¹⁰, the main precursor of type 2 diabetes, occurs when one's blood sugar levels are higher than normal, but not yet high enough to be classified as diabetes. Prediabetes can affect both adults and children. People with prediabetes may exhibit some of the signs, symptoms, and complications of type 2 diabetes. If you do have prediabetes, the long-term damage caused by the condition (especially to the heart, blood vessels, and kidneys) may already be starting.

Without making lifestyle changes, people with prediabetes are likely to progress towards developing type 2 diabetes. However, it is possible to prevent the progression from prediabetes to type 2 diabetes. Making healthy lifestyle choices can help bring blood sugar back to a normal level.

Diabetes causes

Type 2 diabetes develops¹¹ when the pancreas still produces insulin, but the insulin produced isn’t enough or is not processed properly. Unlike type 1 diabetes, type 2 diabetes is usually diagnosed later in life.

Exactly why type 2 diabetes develops is unknown. However, some contributing factors have been identified, including genetics and environmental factors (such as being overweight and/or inactive).

Type 1 diabetes symptoms

The symptoms of type 1 diabetes can appear relatively suddenly. Some common symptoms can include:

• Increased thirst
• Frequent urination
• Increased hunger
• Unexpected weight loss
• Irritability and other mood changes
• Fatigue and weakness
• Blurred vision
• Bedwetting in children who previously didn’t wet the bed during the night

If you or your child experience any of these symptoms, share them with your healthcare provider. He or she will be able to provide you with the proper diagnosis and treatment.

Diabetes symptoms

The symptoms of diabetes mellitus (types 1 and 2) can overlap. They often depend on how much your blood sugar is elevated.

Some of the signs and symptoms of both types of diabetes mellitus include:

• Increased thirst
• Frequent urination
• Extreme hunger
• Unexplained weight loss
• Fatigue
• Irritability
• Blurred vision
• Slow-healing sores
• Frequent infections
• Presence of ketones in the urine (a byproduct of the breakdown of muscle and fat that occurs when there isn’t enough available insulin)

Type 1 diabetes complications

Type 1 diabetes can affect major organs and structures in the body over time, including the heart, blood vessels, nerves, eyes, and kidneys. However, treating the condition by maintaining a normal blood sugar level can dramatically reduce the risk of many complications.

If left untreated, diabetes complications may be disabling or even life-threatening.

Some of the complications¹² caused by type 1 diabetes include:

• Heart and blood vessel disease: Having diabetes dramatically increases your risk of developing various cardiovascular problems, including coronary artery disease (CAD) with chest pain (angina), heart attack, stroke, narrowing of the arteries (atherosclerosis), and high blood pressure (hypertension).
• Nerve damage (neuropathy): Excess blood sugar can injure the walls of the tiny blood vessels, called capillaries, that nourish your nerves (especially those in the legs). This damage can cause tingling, numbness, burning, or pain that usually begins at the tips of the toes or fingers and spreads upward. Poorly controlled blood sugar can eventually cause a loss of feeling in all affected limbs.
• Damage to the nerves that affect the gastrointestinal tract can cause problems like nausea, vomiting, diarrhea, or constipation. Erectile dysfunction may also be an issue in men.
• Kidney damage (nephropathy): The kidneys contain millions of clusters of tiny blood vessels that filter waste from your blood. Diabetes can damage this filtering system. Severe damage can even lead to kidney failure or irreversible end-stage kidney disease.
• Eye damage: Diabetes can damage the blood vessels of the retina, leading to a condition called diabetic retinopathy that can potentially cause blindness. Having diabetes also increases the risk of developing other serious vision problems, including cataracts and glaucoma.
• Foot damage: Poor blood flow or nerve damage in the feet increases the risk of various foot complications. If left untreated, cuts and blisters can become seriously infected, in some cases ultimately requiring toe, foot, or leg amputation.
• Skin and mouth conditions: Diabetes can cause you to be more susceptible to bacterial and fungal skin and mouth infections. Diabetes also puts you at higher risk for gum disease and dry mouth.