Diabetes: Causes, Symptoms, and Treatment
Medically reviewed by Achuta Uppu, MD, Internal Medicine. Last reviewed: October 23, 2026.
What kind of doctor treats Diabetes?
Most people with diabetes see a primary care doctor, such as a family doctor or an internal medicine doctor. An endocrinologist, a doctor who treats hormone problems, can also help. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What is diabetes?
Diabetes is a disease in which your blood glucose, or blood sugar, is too high. Insulin helps move glucose from your blood into your cells, where it is used for energy. With diabetes, your body cannot make insulin, cannot use insulin as well as it should, or both. Over time, high blood glucose can cause serious health problems. There are different types of diabetes.
- Type 1 diabetes: your body makes little or no insulin.
- Type 2 diabetes: this is the most common form.
- Gestational diabetes: this form develops during pregnancy.
Prediabetes means your blood glucose is higher than normal but not high enough to be called diabetes.
Symptoms
Symptoms may include:
- Feeling very thirsty and very hungry.
- Peeing more often, including at night.
- Feeling very tired and having blurry vision.
- Numbness or tingling in the feet or hands.
- Sores that do not heal.
Type 1 diabetes symptoms usually come on quickly and can be severe. With type 2 diabetes, symptoms often develop slowly, over several years, and can be so mild that you might not notice them.
Causes and who gets it
Researchers think genes and things in the environment might trigger type 1 diabetes. Type 2 diabetes has several causes, including genes and lifestyle. Lifestyle causes include not being active and being overweight. You are at higher risk of type 2 diabetes if you:
- Are over age 35.
- Have a family history of diabetes.
- Have prediabetes.
How doctors diagnose it
Your doctor can diagnose diabetes using blood tests. Common tests are:
- A1C test: a blood test that shows your average blood glucose over the last 3 months.
- Fasting glucose test: measures your blood glucose at one point in time.
- Random glucose test: used when you have symptoms and your doctor does not want you to fast for 8 hours first.
Diabetes is shown by an A1C of 6.5% or above, or a fasting glucose of 126 mg/dL or above. Your doctor will usually use a second test to confirm it.
Treatment
- Type 1 diabetes: you will need daily insulin, either by injection or through a special pump.
- Type 2 diabetes: you may be able to manage or even reverse it with lifestyle changes. Some people also need medicines.
- Gestational diabetes: healthy eating and exercise may lower your blood glucose.
Take your medicines as they were prescribed, even if you feel good or have reached your goals. Try to get at least 150 minutes of moderate exercise, such as brisk walking, each week. For most people with diabetes, the A1C goal is below 7%, but yours may differ if you have other health problems. Glucagon, a hormone that raises blood glucose, is the best way to treat severely low blood glucose.
When to see a doctor
Anyone with symptoms of diabetes should be tested. Tell your health care team if your glucose is often too high or too low. Diabetic ketoacidosis, or DKA, is an emergency that needs care right away. Signs of DKA include feeling very tired, trouble breathing, fruity-smelling breath, and fainting. Very low blood glucose may cause confusion or fainting. Very high blood glucose may also cause confusion or fainting. Call 911 or go to the emergency room if you have signs of DKA, or if you faint or become confused from very low or very high blood glucose.
How a direct primary care or concierge doctor fits in
A direct primary care doctor charges a flat monthly fee instead of billing insurance, while a concierge doctor usually charges more and often works alongside insurance. A direct primary care or concierge doctor can talk with you about your goals and whether your diabetes care plan needs changes. They can also help you work with a dietitian or a diabetes educator.
Common questions
Can type 2 diabetes be reversed?
Sometimes it can. People with type 2 diabetes may be able to manage or even reverse it with lifestyle changes. These changes are a healthy diet, a healthy weight, and regular exercise.
Can diabetes be prevented?
Sometimes. You may be able to delay or prevent type 2 diabetes with the same lifestyle changes used to manage diabetes. They may also help prevent diabetes in pregnancy.
How often should I be tested for diabetes?
It depends on your risk. Experts say you should be tested for type 2 diabetes regularly if you have certain risk factors. People with normal test results should be retested every 3 years. People diagnosed with prediabetes should be tested every year.
Can a home blood glucose meter diagnose diabetes?
No. A blood glucose meter that you can buy over the counter cannot diagnose diabetes.
Sources
- MedlinePlus - Diabetes
- National Institute of Diabetes and Digestive and Kidney Diseases - Diabetes Tests & Diagnosis
- National Institute of Diabetes and Digestive and Kidney Diseases - Managing Diabetes
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
