Differences Between Type 1 and Type 2 Diabetes

Ruben Castaneda

How much do you know about diabetes? It's one condition, but there are several distinct types of the disease. Each has its own causes and risk factors. Diabetes is one of the more common diseases in the U.S. -- more than 30 million in the country have it as of 2015, according to the 2017 National Diabetes Statistics Report, a publication of the Centers for Disease Control and Prevention. That's more than 9 percent of the U.S. population.

Millions of people don't know they have diabetes. More than 7 million people -- 24 percent of the total number of people with the disease -- weren't aware or didn't report having diabetes, according to the report. Meanwhile, the number of people in the U.S. who are overweight or obese -- which are risk factors for diabetes -- continues to increase. Therefore, the number of people with diabetes is expected to grow, experts say. "Millions of people have diabetes and don't know it," says Dr. Garth Graham, a practicing cardiologist and president of the Aetna Foundation in Hartford, Connecticut. "According to the report, nearly a quarter of the total number of people with diabetes either weren't aware or didn't report having the disease."

Diabetes can lead to a raft of health problems, including heart attacks, blindness, strokes and kidney failure. Many diabetics experience peripheral neuropathy. That means poor blood sugar control over time that can lead to pain, tingling or a lack of feeling in your hands and feet. If you don't have feeling in your feet, you could suffer an injury and not feel it, which in turn can lead to an infection that, if not treated, could require amputation.

Given its prevalence, being educated on diabetes, including how to manage it, is important. Here are the basic differences among prediabetes, Type 1 diabetes, Type 2 diabetes and gestational diabetes:

Types of Diabetes

1. Prediabetes is a precursor to Type 2 diabetes, says Judith Wylie-Rosett, co-director of the New York Regional Center for Diabetes Translational Research at Albert Einstein College of Medicine in New York City. She's a co-author of "101 Weight Loss Tips for Preventing and Controlling Diabetes" and an associate editor of the journal Diabetes Care. An estimated 34 percent of adults in the U.S. -- more than 84 million people -- had prediabetes in 2015, according to the 2017 National Diabetes Statistics Report. If not treated, prediabetes often leads to Type 2 diabetes, according to the CDC.

2. Type 1 diabetes occurs when your body doesn't produce sufficient insulin, a hormone secreted by beta cells in the pancreas. Insulin allows your body to use sugar from carbohydrates for energy. It also helps your body store glucose for future use and keeps your blood sugar level from getting too high or too low, says Dr. Mary Vouyiouklis Kellis, an endocrinologist at the Cleveland Clinic. Type 1 diabetes is often inherited. It's commonly diagnosed in children and young adults who were born with it, which is why it was once called juvenile diabetes, Kellis says. Doctors can, however, diagnose it in adults.

3. Type 2 diabetes is by far the most common kind of diabetes, says Dr. Jay Skyler, deputy director for clinical research and academic programs in the Diabetes Research Institute at the University of Miami in Florida. About 95 percent of people with diabetes have Type 2 diabetes, also known as non-insulin dependent diabetes, Skyler says. Unlike insulin-dependent diabetes, people with non-insulin dependent diabetes are able to produce some of their own insulin, but their bodies are unable to use this insulin to completely control blood sugar levels, he says. This is known as insulin resistance. Unhealthy life choices, like not exercising, eating too many unhealthy goods and carrying too much weight, can contribute to a diagnosis of Type 2 diabetes. It usually develops after age 35, although it can occur in younger people as well, especially if they are overweight and have a sedentary lifestyle, Skyler says. Commonly referred to as "adult onset" diabetes, 80 percent of those with this form of diabetes are overweight and have a family history of Type 2 diabetes. Certain ethnic groups have a higher risk of developing this form of the disease, including African-Americans, Hispanics and American Indians, he says. In addition, women who had diabetes during pregnancy are at greater risk of developing Type 2 diabetes later in life.

4. Gestational diabetes. This kind of diabetes only affects pregnant women. Specifically, pregnant women who have never had diabetes but who have high blood sugar levels during pregnancy are considered to have gestational diabetes, according to the American Diabetes Association. The prevalence of gestational diabetes is as high as 9 percent among all pregnant women, according to a 2014 analysis by the CDC. Gestational diabetes starts when your body can't make and use all the insulin it needs for pregnancy. Lacking sufficient insulin, glucose can't leave the blood and be converted to energy, according to the ADA. Therefore, glucose reaches high levels in the blood, causing hyperglycemia. Untreated or poorly controlled gestational diabetes can give your baby high blood glucose levels. This causes the baby's pancreas to produce extra insulin to get rid of the blood glucose. Babies with excess insulin become children who are risk for obesity or adults who are at risk for Type 2 diabetes.

[See: 10 Myths About Diabetes.]

Diagnosing Diabetes

Prediabetes diagnosis. Fasting blood sugar is a measure of the glucose (a type of sugar) in your blood after you haven't eaten for at least 12 hours. A fasting blood level between 100 and 125 indicates prediabetes. The higher a person's number, the closer he or she is to developing Type 2 diabetes. However, diet and exercise can prevent prediabetes from progressing. "If somebody has a fasting glucose of 124, (he or she) is probably more likely to develop Type 2 diabetes," Wylie-Rosett says. "But research has shown that in people who lose weight, if they lose weight (7 percent of their body weight) their odds (of developing Type 2 diabetes) drops by 58 percent." Prediabetes can be diagnosed with another blood test, which measures your hemoglobin A1C number. This figure measures your average blood sugar over a three-month span.

Type 1 diabetes diagnosis. The diagnosis for Type 1 diabetes is typically done with an A1C blood test, which measures your average blood sugar levels for the past two or three months, according to the Mayo Clinic. Your doctor can also use other blood screenings to test for the condition. A random blood sugar test involves a blood sample taken at random to measure blood sugar values. Regardless of when you last ate, a random blood sugar level of 200 milligrams per deciliter or higher suggests diabetes, particularly when coupled with symptoms like frequent urination and extreme thirst. A fasting blood sugar blood test can be taken after an overnight fast. With this test, a fasting blood sugar level of 126 or higher on two separate tests shows diabetes.

Type 2 diabetes diagnosis. Type 2 diabetes is typically diagnosed using the A1C blood test, according to the Mayo Clinic. An A1C level of 6.5 percent or higher on two separate tests means you have diabetes. A random blood sugar test, a fasting blood sugar test and an oral glucose tolerance test can also be used to diagnose Type 2 diabetes.

Gestational diabetes diagnosis. If you're pregnant, your doctor will probably evaluate your risk factors early in your pregnancy. If your body mass index before pregnancy was 30 or higher or you have a close relative with diabetes, you're at risk of gestational diabetes. In that case, your doctor may test you for gestational diabetes during your initial prenatal visit. If you're at average risk, your physician will probably have a screening test during your second trimester. A blood test measuring your blood sugar level is used to screen for gestational diabetes. You'll drink a syrupy glucose solution before the test. Your doctor may order a follow-up blood test. If your blood sugar readings are higher than normal in the follow-up test, you'll be diagnosed with gestational diabetes.

Diabetes Symptoms

-- Prediabetes symptoms. There are typically no symptoms for prediabetes. One possible sign that you may be at risk for developing Type 2 diabetes is darkened skin, particularly on your neck, armpits, elbows, knees and knuckles, Wylie-Rosett says.

-- Type 1 diabetes symptoms. Signs and symptoms of Type 1 diabetes include increased thirst, frequent urination, blurry vision, extreme hunger, unintentional weight loss, fatigue, weakness and mood swings, Kellis says.

-- Type 2 diabetes symptoms. The array of Type 2 diabetes symptoms includes increased thirst, frequent urination, unintended weight loss, fatigue, blurred vision, slow-healing sores, frequent infections, areas of darkened skin and increased hunger, according to the Mayo Clinic.

-- Gestational diabetes symptoms. For most women, gestational diabetes doesn't cause noticeable signs or symptoms, according to the Mayo Clinic.

Treatments

Prediabetes treatment. The treatment for prediabetes involves adopting healthy habits, according to the Mayo Clinic. These include eating healthy foods low in fat and calories and high in fiber; becoming more physically active and exercising moderately for 30 to 60 minutes daily; and losing excess weight. If you smoke, stop. Your doctor may prescribe medications to control your cholesterol and high blood pressure.

Type 1 diabetes treatment. There's an array of treatments for Type 1 diabetes, Graham says. These include taking insulin, which could be short-, rapid-, intermediate- or long-acting. Insulin can be administered though injections or by a pump that you wear throughout the day. In addition, your doctor will likely prescribe lifestyle changes like eating foods low in fat and calories and high in nutrients, exercising regularly and maintaining a healthy weight.

Type 2 diabetes treatment. The treatment for Type 2 diabetes is similar to the way Type 1 is treated. Treatments include weight loss, healthy eating, regular exercise, blood sugar and, if needed, diabetes medication or insulin. Blood sugar monitoring is typically part of the treatment for Type 1 and Type 2 diabetes.

Gestational diabetes treatment. To treat gestational diabetes, you'll typically start by monitoring your blood sugar. Eating a healthy diet that focuses on fruits, vegetables and whole grains, exercising regularly and taking insulin if necessary are also part of the treatment regimen. You should closely observe your baby's growth and development with ultrasounds and other tests. If you don ' t go into labor by your due date or sometimes earlier , your doctor may induce labor. Giving birth after your due date may increase the risk of complications for you and your baby.

[See: The Best Foods to Prevent and Manage Diabetes]

What Is the Difference Between Type 1 and Type 2 Diabetes?

Both Type 1 and Type 2 diabetes are chronic diseases that affect the way your body regulates glucose, says Dr. Naunihal Virdi, medical director for the U.S. and Canada at Abbott Diabetes Care. Type 1 diabetes is often inherited, and it commonly develops in childhood. About 5 percent of the more than 30 million people in the U.S. with diabetes have Type 1 diabetes, according to the American Diabetes Association. Type 2 diabetes, on the other hand, develops over time, and is much more common than Type 1, Virdi says. Among people with diabetes, 90 to 95 percent have Type 2 diabetes, according to the CDC. With Type 2 diabetes, your body's cells aren't as sensitive to insulin, so your pancreas has to make more insulin to produce the same effect. This is called insulin resistance. Over time, elevated glucose levels result in damage to the body's tissues, which can lead to diabetic neuropathy, kidney failure and vision loss.

Type 1 and Type 2 Diabetes Causes

Family history, genetics and age are risk factors for Type 1 diabetes. While Type 1 diabetes can appear at any age, it occurs at two noticeable peaks, in children ages 4 to 7 and kids ages 10 to 14, according to the Mayo Clinic.

Type 2 diabetes usually develops after age 35, though it can occur in younger people as well, especially if they are overweight and have a sedentary lifestyle, Skyler says. In addition, women who had diabetes during pregnancy are also at greater risk of developing Type 2 diabetes later in life.

How to Diagnose Type 1 Diabetes Versus Type 2

Type 1 diabetes can develop quickly, often in childhood, Virdi says. Many patients with Type 1 diabetes are diagnosed because they have symptoms associated with elevated glucose levels, such as needing to urinate frequently. On the other hand, because Type 2 diabetes develops over time, many patients don't have symptoms and aren't immediately aware they have diabetes, Virdi says.

While there are differences between Type 1 and Type 2 diabetes, both are diagnosed with blood tests. The diagnosis for Type 1 diabetes is typically done with an A1C blood test; an A1C level of 6.5 percent or higher on two separate tests means you have diabetes. Your physician can also use other bloods tests to screen for Type 1 diabetes.

How Are Type 1, Type 2 and Gestational Diabetes Treated?

There's an array of treatments for Type 1 diabetes, Graham says. These include taking insulin, which could be short-acting, rapid-acting, intermediate or long-acting. In addition, your doctor will likely prescribe lifestyle changes such as carbohydrate, fat and protein counting, frequent blood sugar monitoring, eating healthy foods, exercising regularly and maintaining a healthy weight. Insulin can be administered through injections or through a pump that you wear throughout the day.

Managing Type 2 diabetes can be challenging, but it's something you need to do in order to decrease potential for complications and keep your blood sugar at appropriate levels, Graham says. Treatment of Type 2 diabetes includes weight loss, healthy eating, regular physical exercise of at least 150 minutes per week, possible diabetes medication, insulin therapy and blood sugar monitoring. A healthy diet involves decreasing your intake of calories, saturated fats and refined carbohydrates while eating more fruits, vegetables and offerings high in fiber. Because individuals with diabetes also have many of the same risk factors for heart disease, your doctor will also advise you to closely monitor your intake of sodium. Most salt that we consume comes from packaged and processed foods, not from adding salt. The American Heart Association recommends no more than 2,300 milligrams of sodium per day and to try to lower your intake to 1,500 milligrams per day.

There are a number of medications that can help manage Type 2 diabetes, Graham says. These include metformin, sulfonylureas, meglitinides, DPP-4 inhibitors, GLP-1 receptor agonists, SGLT-2 inhibitors and insulin. In addition to medications, your doctor might prescribe low-dose aspirin therapy to prevent heart and blood vessel disease.

[See: Got Diabetes? 7 Ways to Improve Your Sex Life]

If you're diagnosed with gestational diabetes, you'll need to monitor and control your blood sugar to keep your baby healthy and avoid complications during your pregnancy or delivery, according to the Mayo Clinic. To monitor your blood sugar, you draw a drop of blood from your finger using a small needle and place it on a test strip. You'll then insert the strip into a blood glucose meter, a device that measures and displays your blood sugar level. Eating a healthy diet focusing on foods high in nutrients and low in fat and calories, such as fruits, vegetables and whole grains, is part of the treatment regimen. Regular exercise also helps protect against gestational diabetes. If diet and exercise aren't enough, you may need insulin injections to lower your blood sugar.