A Patient's Guide to Diabetes

Diabetes is the seventh leading cause of death in the U.S., according to the Centers for Disease Control and Prevention. Overall, more than 30 million people in the U.S. – more than 9 percent of the country's population – have diabetes, according to the CDC. In addition, more than 84 million people in the U.S. have prediabetes. People with prediabetes have blood sugar levels that are elevated but not quite high enough to be classified as Type 2 diabetes, the most common type of the disease. Aside from Type 1 and Type 2 diabetes, there's gestational diabetes, which can develop during pregnancy in some women who don't have diabetes. Despite its prevalence, 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 they had diabetes or didn't report having it, according to the 2017 National Diabetes Statistics Report, a CDC publication.

Types of Diabetes

1. Type 2 diabetes is far and away the most common type of diabetes. About 95 percent of people with the disease have Type 2 diabetes. This type of diabetes is also known as non-insulin dependent diabetes. That means that unlike insulin-dependent diabetes, people with Type 2 diabetes are able to produce some of their own insulin. However, their bodies are unable to use this insulin to completely control blood sugar levels. This is known as insulin resistance. An unhealthy lifestyle – like not exercising, eating too many fatty and high-calorie, nutrient-poor foods and carrying too much weight – can contribute to a diagnosis of Type 2 diabetes. This kind of diabetes typically develops after age 35 and is known as "adult onset" diabetes. However, it can occur in younger people, especially if they carry too much weight and have a sedentary lifestyle. Overall, 80 percent of those with Type 2 diabetes are overweight and have a family history of this type of the disease. African-Americans, Hispanics and American Indians have a higher risk of developing Type 2 diabetes.

2. Type 1 diabetes is an autoimmune disease. It occurs when your body doesn't produce sufficient insulin, a hormone secreted by beta cells in the pancreas. Insulin allows your body to convert sugar from carbohydrates for energy, store glucose for future use and also regulates your blood sugar level so it doesn't get too high or low. It's common for Type 1 diabetes to be inherited. This type of the disease is commonly diagnosed in kids and young adults who are born with it; it was once known as juvenile diabetes. However, physicians can diagnose it in adults.

3. Gestational diabetes is a condition that only affects pregnant women – to be precise, pregnant women who have never had diabetes but who have high blood sugar levels during pregnancy. Annually, between 2 and 10 percent of pregnancies in the U.S. are affected by gestational diabetes, according to the CDC.

4. Prediabetes. About a third of the U.S. adult population – more than 84 million people – have prediabetes. If not treated, prediabetes often leads to Type 2 diabetes within five years.

Causes of Diabetes

Type 2 diabetes. Type 2 diabetes occurs when your body becomes resistant to insulin or when the pancreas fails to produce enough insulin, according to the Mayo Clinic. Insulin is a hormone that's produced by a gland behind and below the stomach. Insulin lowers the amount of sugar in your bloodstream. Precisely why a body becomes resistant to insulin or why its pancreas doesn't produce sufficient insulin is unknown, though genetics seem to be a contributing factor. Being overweight and physically inactive are also believed to play a role.

Type 1 diabetes. Type 1 diabetes is an autoimmune condition. People with this type of diabetes have an immune system that is engaged in too little or too much activity. This can compromise the immune system's ability to keep the body from getting sick. In Type 1 diabetes, beta cells, which are found in the pancreas and produce insulin, are destroyed. Your body uses insulin to convert carbohydrates you consume into fuel. With Type 1 diabetes, your body doesn't produce enough insulin, according to the Mayo Clinic. The exact cause of Type 1 diabetes is unknown. In people who have this type of diabetes, usually the body's own immune system – which normally fights harmful bacteria and viruses – mistakenly destroys insulin-producing cells, or islets, in the pancreas. Once a significant number of islet cells are destroyed, "you'll produce little to no insulin," according to the Mayo Clinic. People with a parent or sibling with Type 1 diabetes have a slightly increased risk of developing the condition, according to the Mayo Clinic. Genetics and age play a factor as well. While Type 1 diabetes can appear at any age, it occurs at two noticeable peaks, according to the Mayo Clinic. The first peak occurs in children between 4 and 7 years old, and the second peak is in kids between ages 10 and 14.

Gestational diabetes. Having a family history of diabetes and being overweight or obese can increase a pregnant woman's risk of gestational diabetes. Women over age 25 are at greater risk of developing gestational diabetes. Also, for reasons that aren't clear, black, Hispanic, American Indian or Asian women are at greater risk of developing gestational diabetes, according to the Mayo Clinic.

Prediabetes. The precise cause of prediabetes is uknown, according to the Mayo Clinic. However, it appears that family history and genetics are important factors. Inactivity and excessive fat, particularly around the abdomen, are also factors.

Diagnosis

Health care professionals can use a glycated hemoglobin or A1C test to diagnose Type 1 and Type 2 diabetes and prediabetes, according to the Mayo Clinic. The higher your blood sugar levels, the more hemoglobin you'll have with sugar attached, according to the clinic. An A1C level of 6.5 percent or higher on two separate tests indicates you have diabetes. A random blood sugar test, a fasting blood sugar test and an oral glucose tolerance test can also be used to screen for diabetes.

To test for gestational diabetes, your doctor may use an initial glucose challenge test. this involves drinking a syrupy glucose solution an hour before you have a blood test to measure your blood sugar level. If your blood sugar level is higher than normal, your doctor will order a follow-up test to determine if you have gestational diabetes, according to the clinic. The follow-up test consists of fasting overnight and drinking another sweet solution, one that has an even higher concentration of glucose. Then your blood sugar level will be checked every hour over a span of three hours. If at least two of the blood sugar readings are higher than the normal values established in each of the three hours of the test, you'll be diagnosed with gestational diabetes, according to the clinic.

Symptoms

Type 2 diabetes

According to the Mayo Clinic, signs and symptoms of Type 2 diabetes include:

Men may also suffer from erectile dysfunction, caused by nerve and artery damage triggered by high blood pressure. Also, higher blood sugar levels can promote yeast growth and infections, and many men suffer from urinary tract infections.

Women may also experience urinary tract infections and vaginal yeast infections. Yeast and bacteria feed on glucose, which can contribute to infections of the female urinary tract.

Type 1 diabetes

The symptoms of Type 1 diabetes are similar to those of Type 2 diabetes, according to the Mayo Clinic. They include:

Gestational diabetes

Most women don't have noticeable signs or symptoms of gestational diabetes, according to the Mayo Clinic.

Prediabetes

There are several symptoms for prediabetes, according to the Mayo Clinic. They include:

Early Signs in Women

Women and men share many of the same early signs of diabetes. For instance, some women and men can have urinary tract infections. Some women may experience frequent vaginal yeast infections. Some women may also have breath that smells fruity or sweet. This is caused by a high level of ketones in the blood. Ketones are chemicals produced in your liver when your body has insufficient insulin to turn glucose into energy.

Early Signs in Men

Because of nerve and artery damage triggered by high blood pressure, diabetes can triple men's likelihood for erectile dysfunction, says Dr. Garth Graham, a practicing cardiologist and president of the Aetna Foundation in Hartford, Connecticut. Many men also experience urinary tract infections caused by higher blood sugar levels, which promote yeast growth and infections.

Complications

Type 1 diabetes can cause an array of serious complications, according to the Mayo Clinic. These include:

Type 2 diabetes can also cause a raft of serious complications, including:

Treatments

Type 1 diabetes is treated with insulin, according to the American Diabetes Association. Insulin is a hormone that controls the blood sugar in your body. Most people with insulin need at least two shots a day, but some will need three or four, according to the medical journal American Family Physician. Insulin is typically injected with a small needle. You can also use an insulin pen. People with Type 1 diabetes must constantly monitor what they eat, their physical activity, stress levels, sleep patterns, medications and illnesses, according to Toby Smithson, a registered dietitian and former national spokesperson for the Academy of Nutrition and Dietetics. She's also a certified diabetes educator for Livongo, a consumer digital health company that provides technology solutions and education to people with chronic conditions to help them live better and healthier lives.

Type 2 diabetes management and treatment involves an array of approaches, according to the Mayo Clinic. They include:

Health Care Providers That Treat Diabetes

Diets

U.S. News asked a group of nutrition experts to evaluate the best diets for diabetes. They came up with the U.S. News 2019 Best Diabetes Diets, which has the Mediterranean diet at the top of the list.

Wendy Gregor, a registered dietitian and certified diabetes educator with Cecelia Health, provides these diet strategies for people with diabetes:

People with Type 1 diabetes need to match their food carbohydrate consumption in each meal or snack to their dose of fast-acting insulin, Gregor says. "So, for this group, knowing the carbohydrate content of foods is priority number one," she says. "Being a carb-counting expert is a critical skill." An accurate match between carbs and insulin will reduce the risk of big highs and lows in blood sugar.

People with Type 2 diabetes have a bit more flexibility. "Understanding which foods have carbohydrates is important, so knowing which food groups contribute carbs is the key," Gregor says. "You don’t have to be a carb-counting expert to be successful. Limiting the portions of carb-rich foods to about one-fourth of your meal will have wonderful results." People with Type 2 diabetes should distribute their carbohydrate intake throughout the day by eating small meals and snacks. They should take a short walk after meals. This will help their body move sugar from the blood into muscle cells.

Women with gestational diabetes need to really watch the distribution of carbohydrates across the day, spreading them out carefully, so that they don't exceed their body's ability to process those carbs each time they eat. These women are especially carb-sensitive first thing in the morning.