Diabetes is a disease characterized by high blood glucose levels. Blood glucose, also known as blood sugar, is the main source of energy for your body and comes from the food you eat. 

When you consume food, your pancreas releases a hormone called insulin, which “unlocks” your cells so that the glucose in your blood can enter them to fuel your body’s functions. Sometimes, a problem with insulin occurs that keeps glucose in your blood instead of moving it into the cells:

  • Your body doesn’t make insulin, and none of the sugar in your blood makes it into the cells.
  • Your body doesn’t make enough insulin, and only some of the glucose in your blood makes it into the cells.
  • Your body doesn’t use insulin properly, and only some glucose makes it into the cells.

All three of these scenarios cause high levels of glucose in the blood. Over time, elevated glucose can cause diabetes, which is a very serious disease that’s chronic—meaning long-term—and progressive, which means that without treatment, it will get worse.

What are the three most common types of diabetes?

The three most common types of diabetes are type 1, type 2, and gestational diabetes.

Type 1 diabetes

If your pancreas doesn’t make insulin, you have type 1 diabetes. Type 1 diabetes occurs when your immune system recognizes the cells in your pancreas as invaders and destroys them. People who have type 1 diabetes have to take insulin every day in order to stay alive. Type 1 diabetes is usually diagnosed during childhood or young adulthood, but it can develop at any age. Although researchers are certain what causes type 1 diabetes, experts think it’s caused by a combination of genetics and environmental factors, which may include viruses. 

Is type 1 diabetes genetic?

Type 1 diabetes often runs in families. Even if you don’t have type 1 diabetes, or even symptoms of it, you can get tested for the associated autoantibodies. If you test positive for them, you have a higher chance of developing type 1 diabetes at some point in your life. People over the age of 20 who have a parent, sibling, or child with type 1 diabetes may want to get tested—as may someone 20 years old or younger who has a grandparent, parent, aunt or uncle, niece or nephew, cousin, sibling, or half-sibling.

Symptoms of type 1 diabetes

Type 1 diabetes symptoms usually appear over a few days or a few weeks, and they can be serious. Symptoms of type 1 diabetes include:

  • Increased hunger
  • Increased thirst
  • Increased urination
  • Unexplained weight loss
  • Blurred vision
  • Fatigue

In some cases, a life-threatening condition called diabetic ketoacidosis, or DKA, is the first indication of a problem. Some of the symptoms of DKA include:

  • Stomach pain
  • Nausea or vomiting
  • Difficulty breathing
  • Confusion or difficulty concentrating
  • Dry or flushed skin
  • Fruity-smelling breath

How is type 1 diabetes diagnosed?

If someone has clear symptoms of diabetes, their physician will use the random plasma glucose (RPG) test to measure your blood glucose at a single point in time. If your blood glucose is high when the test is administered, it may be followed up with the glycated hemoglobin test, better known as the A1C test, which indicates your average blood sugar levels over the past three months. While these tests can confirm that you have diabetes, they don’t tell your doctor which type you have. To determine the type, an autoantibody test may be performed. Autoantibodies are antibodies that mistakenly attack your cells and tissues, even if they’re healthy. Certain autoantibodies are commonly detected in cases of type 1 diabetes, but not in type 2 diabetes.

How is type 1 diabetes treated?

People with type 1 diabetes need insulin, but since their pancreas doesn’t produce it, they have to take it by injection with a syringe, via an insulin pen, or through an insulin pump. In some cases, additional medications may be needed to reduce the amount of sugar in the blood after eating. In the past few years, the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) has funded a number of studies on devices that may serve as an artificial pancreas to help people manage type 1—and possibly type 2 and gestational—diabetes.

Type 2 diabetes

If your pancreas doesn’t produce enough insulin—or your body doesn’t use insulin properly—you may develop type 2 diabetes, which is the most common type. Although type 2 diabetes usually occurs in middle-aged and older adults, it can occur at any age.

Is type 2 diabetes genetic?

Inherited gene mutations and a family history of diabetes are risk factors for developing type 2 diabetes, and this disease is more common in Black, Hispanic/Latino, American Indian, Asian American, and Pacific Islander populations. Other risk factors for type 2 diabetes include a poor diet, physical inactivity, increasing age, high blood pressure, and smoking.

Symptoms of type 2 diabetes

Some, but not all, of the symptoms of type 2 diabetes overlap with type 1 diabetes symptoms, but while type 1 symptoms typically appear over a short period of time, symptoms of type 2 diabetes tend to develop over the course of several years. In many cases, the symptoms are mild and don’t feel concerning to the person experiencing them. In other cases, symptoms may not occur at all. Many people don’t learn they have type 2 diabetes until it starts causing health problems like heart disease or blurred vision. 

Common type 2 diabetes symptoms include:

  • Increased hunger
  • Increased thirst
  • Increased urination
  • Unexplained weight loss
  • Blurred vision
  • Fatigue
  • Numbness or tingling in the hands or feet
  • Sores that don’t heal

How is type 2 diabetes diagnosed?

Type 2 diabetes is most commonly diagnosed using the A1C. Other diagnostic tests include a random blood sugar test, which is performed regardless of when you last ate, a fasting blood sugar test, which is administered after fasting overnight, and an oral glucose tolerance test (OGTT), which involves fasting overnight then drinking a sugary liquid and having blood sugar levels tested periodically for several hours.

Experts recommend routine screening for type 2 diabetes for anyone aged 45 or older, anyone between the ages of 19 and 44 who are overweight or obese and have at least one other risk factor for diabetes. Women who had gestational diabetes should also have routine tests to check for type 2 diabetes.

How is type 2 diabetes treated?

Type 2 diabetes can’t be cured, but it can be effectively managed through a combination of lifestyle changes, including eating a nutritious diet, getting regular exercise, losing weight if necessary, and monitoring your blood sugar daily. In some cases, medication for diabetes may be prescribed, including metformin, the most common diabetes medication, or insulin therapy. If you have high cholesterol or high blood pressure, you may also be prescribed medication to keep those conditions under control.

Gestational diabetes

Some women who are pregnant develop gestational diabetes, which typically—but not always—goes away on its own after the baby is born. Gestational diabetes can cause health problems for the mother and baby, so managing the condition is essential for maternal and child health. Women who develop gestational diabetes have a higher risk of developing type 2 diabetes later on. In some cases, pregnant women who are diagnosed with gestational diabetes actually have type 2 diabetes.

Is gestational diabetes genetic?

Your genes may play a role in the development of gestational diabetes, and being overweight is another important risk factor. Sometimes, this condition is related to changes in hormones that occur during pregnancy.

Symptoms of gestational diabetes

Often, gestational diabetes doesn’t produce symptoms, or symptoms may be mild, such as increased thirst and urination, which some women may attribute to the pregnancy itself. 

How is gestational diabetes diagnosed?

Pregnant women are routinely tested for gestational diabetes between weeks 24 and 28 of their pregnancy. A glucose challenge test, also known as the glucose screening test, is administered an hour after you drink a sweet liquid that contains glucose, and if your blood glucose is high, your doctor may have you return for an oral glucose tolerance test (OGTT). 

How is gestational diabetes treated?

Treatment for gestational diabetes centers around lifestyle changes, including eating a nutritious diet and exercising daily. If these don’t lower your blood glucose to a healthy range, you may need to use insulin to keep your blood sugar moving out of the blood and into the cells.

Once the baby is born, it’s important to take steps to reduce your risk for type 2 diabetes—and your child’s risk, since gestational diabetes increases the risk of your child becoming obese or developing type 2 diabetes.

What health problems can diabetes cause?

When blood glucose levels are high for a long period of time, regardless of the type of diabetes you have, a number of serious health problems may develop. Complications of diabetes include:

  • Heart disease
  • Kidney disease
  • Dental diseases
  • Stroke
  • Nerve damage
  • Eye problems
  • Foot problems

Once you’re diagnosed with diabetes, it’s important to keep your blood sugar under control with insulin for type 1 diabetes and with healthy lifestyle changes for type 2 and gestational diabetes. Managing diabetes requires understanding and monitoring your blood sugar levels, following a diabetes meal plan, exercising regularly, and coping with your illness in healthy ways. Lowering your cholesterol and blood pressure if they’re elevated is also crucial for managing the disease, as is quitting smoking and drinking in moderation, if at all. 

Forward helps you prevent or manage diabetes

If you’re at risk for diabetes or you’ve been diagnosed with it, Forward can help you manage it. As your primary care provider, Forward provides genetic and blood testing, along with other health assessments, to determine your risk for diabetes, heart disease, cancer, and other diseases. Personalized prevention, treatment, and management plans include ongoing disease and mental health support and monitoring, and all Forward members are invited to take advantage of our doctor-led Heart Health Program as well as weight management and cancer prevention programs. Take control of your health with personalized primary care and app-based, 24/7 access to your results, goals, and your Forward care team.

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