A quick guide to diabetes: what it is, symptoms, testing, and more

Medically reviewed by Neka Miller, PhD on January 23, 2020. Written by Kathryn Wall. To give you technically accurate, evidence-based information, content published on the Everlywell blog is reviewed by credentialed professionals with expertise in medical and bioscience fields.

Learn more about diabetes with this quick guide—including what it is, possible symptoms, testing for diabetes, and more.

What is diabetes?

The pancreas—a gland found in the abdomen—secretes the hormone insulin to tell your body to use or store the glucose (sugar) that circulates throughout the bloodstream following a meal or after you drink a beverage. Diabetes is a chronic health condition that can occur when the body fails to produce insulin or doesn’t respond to it—resulting in high levels of blood sugar.

Type 1 and type 2 diabetes

There are different types of diabetes, including type 1 and type 2 diabetes. In type 1 diabetes, your pancreas is unable to produce insulin. In type 2 diabetes, your body experiences insulin resistance (in other words, your body’s cells don’t respond effectively to insulin). Both of these conditions can be managed with medication and lifestyle changes like increased physical activity.

What causes diabetes?

The underlying cause varies depending on the type of diabetes. Type 1 diabetes occurs when your immune system destroys the insulin-producing cells of the pancreas. This form of diabetes is typically diagnosed in children and young adults, while type 2 diabetes is more prevalent in middle-aged and older adults. Type 2 diabetes can be caused by many possible factors, including lifestyle and genetic factors. It usually begins with the development of insulin resistance—where fat, muscle, and liver cells do not respond effectively to insulin. This leads to higher glucose levels in the bloodstream over time.

Diabetes prevention

If you are at risk for diabetes, there are a number of lifestyle changes you can make that may help prevent it. Becoming more physically active and maintaining a healthy weight are often effective for prevention (exercise can help lower blood sugar and boost insulin sensitivity). Adding more whole grains and fiber to your diet may also reduce the risk of diabetes and promote better blood sugar control.

What are the main symptoms of diabetes?

According to the American Diabetes Association, symptoms of diabetes include:

  • Urinating often
  • Feeling very thirsty or hungry
  • Extreme fatigue
  • Blurry vision
  • Weight loss
  • Sores that do not heal
  • Numbness or tingling in the hands or feet

If you’re experiencing any of these symptoms, your healthcare provider may evaluate you for diabetes and use specific kinds of tests as part of the diagnostic process.

How to test for diabetes

How do healthcare providers test for diabetes? There are two main types of tests that can help determine if someone has diabetes: hemoglobin A1c (HbA1c) and plasma glucose concentration.

  • HbA1c - A hemoglobin A1c test indicates the average sugar level in your blood over the past 2-3 months. Hemoglobin is a key red blood cell protein that glucose (or sugar) molecules can attach to. One’s HbA1c number is expressed as a percent because this test shows the percentage of hemoglobin in red blood cells that’s coated with glucose molecules]. Diabetes is typically diagnosed if someone has an HbA1c value greater than or equal to 6.5%.
  • Plasma glucose concentration - The fasting plasma glucose (FPG) and oral glucose tolerance test (OGTT) are common examples of plasma glucose concentration tests. A plasma glucose concentration test directly measures one’s at-the-moment blood sugar level (vs. giving an average from the past several months). Results are usually expressed in terms of milligrams per deciliter (mg/dL). With the fasting plasma glucose test, an 8 hour fast is required before a blood sample is collected. In the case of an oral glucose tolerance test, you’ll have your blood sugar level measured before and 2 hours after you drink a glucose-containing liquid.

In addition to these blood tests, a healthcare provider will also consider someone’s symptoms and other factors when making a diagnosis.

How to test for diabetes at home

There isn’t a home diabetes test for the simple reason that diagnosing diabetes requires a physician’s evaluation of any symptoms, as well as interpretation of laboratory test results in the context of underlying health conditions someone might have—plus other factors.

That being said, it is possible to test your HbA1c from the convenience of home with an easy-to-use, at-home A1c test kit. With this test, you just collect a small sample of blood (via a simple finger prick) and send it to a lab for analysis (with prepaid shipping)—and you can conveniently access your results on our secure, online platform.

Treatment options

If you’re diagnosed with diabetes, lifestyle changes—such as dietary adjustments and increased exercise—may help you better control your blood sugar levels. Insulin shots and/or other medications may also be recommended as part of your treatment. The treatment approach recommended for any given person will depend on a number of factors specific to the individual (like one’s blood sugar levels), so it’s important to collaborate closely with one’s diabetes care team when a treatment plan is created.

Easily check your HbA1c level with the Everlywell A1c home test.


1. Insulin, Medicines, & Other Diabetes Treatments. National Institute of Diabetes and Digestive and Kidney Diseases. URL. Accessed January 23, 2020.

2. Type 1 Diabetes. American Diabetes Association. URL. Accessed January 23, 2020.

3. Type 2 Diabetes. American Diabetes Association. URL. Accessed January 23, 2020.

4. What is Diabetes? National Institute of Diabetes and Digestive and Kidney Diseases. URL. Accessed January 23, 2020.

5. Diabetes Symptoms. American Diabetes Association. URL. Accessed January 23, 2020.

6. Goyal R, Jialal I. Diabetes Mellitus Type 2. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020. Available from: URL. Accessed January 23, 2020.

7. Sayed A, Alyafei F, De Sanctis V, Soliman A, Elgamal M. Translating the HbA1c assay into estimated average glucose values in children and adolescents with type 1 diabetes mellitus. Acta Biomed. 2018;89(S5):22-26. doi:10.23750/abm.v89iS4.7357

8. Diabetes diagnosis. American Diabetes Association. URL. Accessed January 23, 2020.

9. Insulin Basics. American Diabetes Association. URL. Accessed January 23, 2020.

Everlywell makes lab testing easy and convenient with at-home collection and digital results in days. Learn More