Let's Talk About Types of Diabetes
These conditions involving high blood sugar may all look the same, but each kind of diabetes has its own causes and treatments. Discover the key differences among the most common types of the disease.
Everyone’s heard of diabetes. But you may not know that there are several different kinds of the disease, each of which develops based on unique factors. The most common ones are type 1 (sometimes referred to as juvenile diabetes), type 2, and gestational diabetes. Knowing which type you have is crucial to getting the care you need. Let’s take a look at the various forms this disease can take.
Our Pro Panel
We went to some of the nation's top experts in diabetes to bring you the most up-to-date information possible.
Katherine Araque, M.D.
Director of Endocrinology
Pacific Neuroscience Institute at Providence Saint John’s Health Center
Santa Monica, CA
Stelios Mantis, M.D.
Rush University Medical Center
Peter Goulden, M.D.
Medical Director of the Division of Endocrinology and Metabolism
Mount Sinai St. Luke's
New York, NY
Type 1, type 2, and gestational diabetes are the three main types. Type 1 is an autoimmune disorder that stops a person’s pancreas from making insulin. In type 2 and gestational diabetes (which only happens during pregnancy), a person’s pancreas makes insulin, but their body doesn’t use it very well.
Type 2 diabetes is usually caused by a combination of factors, including family history, genetic predisposition, ethnicity, body fat, and lifestyle. We know that eating a healthy diet and exercising regularly are two of the best ways you can lower your risk for this disease.
Juvenile diabetes is another term for type 1 diabetes, so-named because type 1 is most often diagnosed in children and adolescents. Similarly, type 2 diabetes, which is usually diagnosed in adults, is sometimes referred to as “adult-onset diabetes.”
It depends on the type. Obviously, gestational diabetes occurs only in women! In type 1, unlike many other autoimmune conditions that occur in women more frequently, both genders are equally likely to get it. And type 2 diabetes actually occurs more frequently in men.
What Is Diabetes Again?
If you have diabetes, no matter what type, you're dealing with a situation of higher-than-normal levels of sugar—or, glucose—in your blood.
The glucose in your blood comes from the protein, carbohydrates, and fats that you eat and drink. During the digestion process, your pancreas releases a hormone called insulin that helps move glucose from the bloodstream into the cells of your body to be used for energy.
But if your body doesn’t produce enough insulin, or can’t use it efficiently, glucose accumulates in your blood, resulting in “high blood sugar.” As time goes on, this extra sugar in the blood causes inflammation and other major health troubles.
About 30 million people in the United States have diabetes mellitus, but nearly one quarter of them don’t know it. Left unchecked, diabetes can cause nerve and blood vessel damage, leading to heart disease, stroke, and even blindness. That’s why screening and early diagnosis are so important.
Here’s what you need to know about the different types of diabetes, and how to tell if you’re at risk.
What to Know About Type 1 Diabetes
Type 1 diabetes is mostly an autoimmune disorder that causes a person’s own immune system to attack and destroy insulin-making cells called beta cells in the pancreas.
When these cells are destroyed or damaged, a person can no longer make their own insulin and must rely on daily insulin injections.
Of the 23 million people in the United States who have been diagnosed with diabetes, just 5% to 10% have type 1. It’s pretty rare: About one in 250 Americans has it.
Most people with type 1 diabetes are diagnosed during childhood or young adulthood. In fact, type 1 is sometimes called “juvenile diabetes” because it is often seen in kids. Diagnosis typically occurs between ages 10 and 16, although some people with type 1 do not develop the disease until their 30s, 40s, or even 50s. About one-fourth of type 1 cases are diagnosed in adults.
Although some autoimmune conditions are more common in women than men, type 1 diabetes happens equally in both genders.
What Causes Type 1 Diabetes?
Doctors don’t know exactly why some people get type 1 diabetes and others don’t. It’s not linked to any particular gene you can test for, and it’s not associated with any specific lifestyle choice you make. These are some of the most likely contributors to developing the disease:
Family history. Although there is no type 1 diabetes “gene,” if autoimmune conditions run in your family, that means you may be at higher risk of developing one, too, including type 1 diabetes. (That said, most people who develop type 1 appear to do so randomly, without a family connection.)
Toxins and infections. Doctors believe that in many cases, a toxin or virus triggers the start of type 1 diabetes. This outside “invader” kicks the immune system into gear to fight it off. The immune system then mistakenly begins to attack the pancreas, killing off insulin-producing beta cells.
Idiopathic. An unusual form of type 1 diabetes with almost complete insulin deficiency, a strong hereditary component, and no evidence of autoimmunity. Reported mainly in Africa and Asia. It is also called Diabetes Type 1b.
Treatment for Type 1 Diabetes
The main treatment for type 1 diabetes is insulin. People with type 1 may need to check their blood glucose four to 10 times a day in order to make decisions about insulin dosages, food, and exercise choices.
Most people use a home glucose meter to monitor their levels. They poke a fingertip with a specialized lancet “pen,” then drop the blood onto a test strip in the meter.
In some cases—especially if you are at high risk of dangerous conditions like low blood sugar or ketoacidosis—your doctor may suggest a continuous glucose monitor. In this case, a tiny sensor is inserted under the skin of your abdomen, arms, or thighs to regularly check glucose levels in body fluids.
When your glucose meter indicates you need insulin, there are a few different ways to take it. (Unfortunately, insulin can’t be taken as a pill because it would be broken down and digested before reaching your blood.) The most common delivery method is an injection with a syringe, usually in the belly, upper arm, thigh, or butt.
Some people prefer using an insulin pump that’s worn on the body and automatically delivers insulin throughout the day through a tiny catheter inserted under the skin.
What to Know About Type 2 Diabetes
The most common type of diabetes, type 2, isn’t an autoimmune disorder. People with type 2 diabetes—also called “adult-onset”—do produce their own insulin, but their bodies don’t use very well. Between 90% to 95% of all people with diabetes have type 2. It usually develops in middle age but is sometimes seen in older kids or teens.
Most people with type 2 don’t need to take insulin, but they may need other medications to help bring down blood sugar levels.
What Causes Type 2 Diabetes?
Type 2 diabetes is caused by a combination of factors. Common things that raise your risk include:
Ethnicity/race. Certain ethnic groups are more likely to develop type 2 than others, including African Americans, Hawaiians, Latinos, Native Americans, Native Alaskans, and Pacific Islanders.
Family history and genetics. There is no single type 2 diabetes “gene” to test for, but if type 2 runs in your family, that means you are at higher risk of developing it, too.
High Body Mass Index (BMI). Higher levels of body fat, especially the kind that gathers in the belly, is linked to insulin resistance and risk of type 2 diabetes. Insulin resistance can also cause more weight gain, creating a frustrating cycle.
Insulin resistance. Type 2 often starts with insulin resistance—meaning that a person’s liver, muscles, and other cells start to respond more slowly or weakly to insulin than they used to. Several things can contribute to insulin resistance, including certain medications, polycystic ovary syndrome, Cushing’s disease, and aging.
Sedentary lifestyle. Physical activity boosts your body’s ability to use insulin efficiently, lowering the risk of high blood sugar. Being sedentary makes your cells less sensitive to insulin, which leads to insulin resistance and increased risk of type 2 diabetes.
Sometimes, type 2 diabetes is caused by an underactive pancreas and your body doesn’t make enough insulin.
Treatment for Type 2 Diabetes
Every person’s type 2 diabetes treatment plan is unique, based on their blood sugar patterns, medical history, lifestyle, and personal preferences. The main components for managing type 2 diabetes include:
Eating thoughtfully. There’s no one best “diabetes diet” everyone should follow, but plant-based meals, a Mediterranean diet rich in vegetables and seafood, and low-carbohydrate plans have all been shown to decrease blood sugar and reduce the risk of developing type 2 diabetes. A registered dietitian or certified diabetes educator can help you find an eating pattern works best for your body, budget, and lifestyle.
Exercising. Physical activity makes your cells more sensitive to insulin. You don’t need to sweat for hours to improve your blood sugar and help manage type 2 diabetes—even a daily walk around the block can help.
Medication. Some people with type 2 diabetes can manage their illness through diet and exercise. But many need medication, too. There are a lot of different drugs that help lower blood sugar—your doctor might recommend one, or a combination, based on your particular case.
What to Know About Gestational Diabetes
Gestational diabetes is characterized by temporary high blood sugar. It happens only during pregnancy and doctors suspect that it’s related to hormonal changes. Most pregnant women are screened for it with a glucose tolerance test during their second trimester.
During the test, you’ll be asked to drink a glucose-containing beverage on an empty stomach and then have your blood drawn to check blood sugar levels. The test can last anywhere from one to three hours, depending on how many times your doctor wants your blood drawn.
Treatment for Gestational Diabetes
Gestational diabetes is usually treated with exercise and diet changes (such as eating less starch and more veggies, fruits, and protein). Some women with gestational diabetes need insulin injections, too.
Most of the time, blood sugar levels go back to normal once the baby is born. But if you develop gestational diabetes during pregnancy, that means you are also at higher than average risk for developing type 2 later in life.
Other Types of Diabetes
There are a handful of other illnesses that commonly fall under the category of “diabetes,” although not all of them are true diabetes mellitus.
Monogenic diabetes: This rare type of diabetes mellitus—which accounts for 1% to 5% of all cases—is caused by a mutation in a single gene. Most of the time in monogenic diabetes, the pancreas struggles to make insulin. The condition is usually found in kids.
Secondary diabetes: Sometimes, certain other diseases can cause high blood sugar that leads to diabetes mellitus, such as Cushing’s syndrome and cystic fibrosis. Specific medications, including niacin, diuretics, HIV medicines, and anti-seizure drugs can also lead to high blood sugar.
Prediabetes: If your blood sugar is higher than normal but not high enough to be diabetes, that’s considered prediabetes. People with prediabetes have an increased risk of developing type 2. Exercise and diet changes are often prescribed to reduce blood sugar and reduce the risk. In some cases, a doctor may also prescribe metformin, a blood-sugar-lowering drug that helps prevent type 2. An estimated 84 million Americans have prediabetes.
Diabetes insipidus: Despite its name, this disease is not related to diabetes mellitus and has nothing to do with high blood sugar. it’s a rare disorder caused by brain or kidney diseases that causes people to urinate up to 20 times more often than people without the condition.
“Type 3” diabetes: This condition not really a type of diabetes at all. Rather, it’s a name some scientists have proposed for Alzheimer’s disease, since some research suggests that one cause of Alzheimer’s may be insulin-resistant cells in the brain.
How Do Doctors Diagnose Diabetes Type?
The first step in getting a diabetes diagnosis is a blood test. If the test comes back positive for diabetes, your doctor will then want to find out which type it is and may want to perform additional testing. Correct diagnosis is very important since treatment is different for the different types. Some diabetes tests include:
Blood Tests for Diabetes
A1C (or glycated hemoglobin) test. This common test measures what percentage of your red blood cells have been coated with glucose over the past two to three months. The higher your blood sugar, the higher your score. An A1C result below 5.7 is considered normal; 5.7 to 6.4 is prediabetic; 6.5 or above suggests diabetes.
Fasting blood sugar test. Blood will be drawn first thing in the morning before you eat or drink anything other than water. A result under 100 milligrams per deciliter is normal; 100 to 125 mg/dL is prediabetic; 126 mg/dL indicates diabetes. Your doctor will likely want to do the test twice before officially diagnosing you.
Glucose tolerance test. This starts out like the fasting blood sugar test. But after getting your blood drawn for the first time, you drink a glucose drink, then blood is drawn again after one to two hours. If your blood sugar is under 140 mg/dL two hours after downing the sugar drink, that’s normal; 140 to 199 is prediabetic; 200 md/dL or over means you have diabetes.
Random blood sugar test. Blood is drawn at any time of day, whether you’ve eaten recently or not. A result of 200 mg/dL indicates diabetes.
Antibody test. To help differentiate between type 1 and type 2 diabetes, your doctor may draw blood for an “autoantibody” test, which will show if your immune system is attacking your pancreas. People with type 1 often test positive for several specific autoantibodies, while those with type 2 (or the rare monogenic diabetes) won’t.
Urine Ketone Test
If your doctor suspects that you have type 1 diabetes, you may need a urine test for ketones. The test can be done at home or in a doctor’s office by peeing into a specimen cup. If you’re doing the test at home, it will come with paper test strips to dip into the urine. Extremely high levels of ketones are a sign of ketoacidosis, a potentially fatal complication of diabetes that requires emergency treatment.
Whatever the tests reveal about the type of diabetes you have, the important thing to remember is that the disease is manageable. Whether you need daily insulin injections or metformin to lower blood sugar, or if your doctor prescribes a Mediterranean diet and daily exercise, you have the ability to control the symptoms of diabetes, so you can get back to living your normal life.
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