Diabetes Symptoms

January 7, 2025

This page was reviewed under our medical and editorial policy by Ping H. Wang, M.D., professor and chair, Department of Diabetes, Endocrinology & Metabolism, City of Hope^® Cancer Center Duarte

Diabetes, also called diabetes mellitus, is a chronic health condition in which levels of sugar (glucose) in the blood are too high. This is due to the body not producing enough insulin, or not being able to use the insulin it makes, to help glucose move out of the blood and into cells for energy. High blood glucose levels lead to a variety of changes in the body and blood vessels, which cause symptoms.

The symptoms of diabetes may happen suddenly or develop gradually over time. Symptoms may also be mild or severe.

While there are other types, the two most common types of diabetes are type 1 and type 2. Patients diagnosed with type 1 diabetes typically experience a sudden onset of symptoms over weeks or a few months. Patients with type 2 diabetes may notice more subtle symptoms and slower onset over years, and many do not realize they have type 2 diabetes until a blood test shows it.

Signs and Symptoms of Diabetes

Symptoms are something a patient experiences, while signs are evidence of disease that a doctor is able to measure.

Some common symptoms are shared by many types of diabetes, but there are also some differences in symptoms and how quickly they come on from one type of diabetes to another. Diabetes symptoms sometimes vary between children and adults and among the different types of diabetes.

Untreated diabetes may lead to some or all of the following symptoms.

Feeling thirsty: People with diabetes may be unusually thirsty and drink more fluids than usual.

Increased urination: Increased fluid intake may lead to more frequent urination as the kidneys try to eliminate excess glucose.

Feeling hungry despite eating: Without the insulin it needs, the body is unable to use glucose for energy, causing increased hunger.

Fatigue: When the body is unable to use glucose properly, a person has less strength and stamina.

Blurred vision: High glucose levels may move fluids from tissues in the eyes, leading to difficulty focusing and blurry vision.

Tingling or numbness in the hands and feet: Nerve damage owing to high blood sugar levels (diabetic neuropathy) may cause tingling or numbness in the extremities.

Unexplained weight loss: Some people with diabetes lose weight because an inability to use glucose properly may cause the body to break down muscle and fat for energy.

Frequent infections and slow-to-heal skin sores: Diabetes may impair the body’s ability to heal wounds and fight infections.

Patients should visit their doctor if they notice any of these symptoms. Diagnosis is made based on a blood test.

Prediabetes Symptoms

Some people have blood sugar levels that are higher than they should be, but not at a level considered full-blown diabetes. This is known as prediabetes, and it increases a person’s risk for developing type 2 diabetes (and heart disease and stroke).

With prediabetes, insulin is not used efficiently to help glucose get into cells for energy. Most of the time, people with prediabetes do not feel any symptoms.

A person may have prediabetes for years and not notice any real symptoms. Getting blood sugar testing on a regular basis and talking to a doctor are ways to be aware of blood sugar levels.

Doctors may recommend a regular blood sugar test for patients who have certain risk factors for prediabetes.

Patients who are at increased risk include those who are overweight, inactive or from certain racial and ethnic groups, including African Americans, Hispanic/Latino, American Indian, Alaska Native or Pacific Islanders. Patients who had gestational diabetes during pregnancy or who gave birth to a baby weighing more than nine pounds also have an increased risk.

Gestational Diabetes Symptoms

Gestational diabetes is a form of diabetes that occurs during pregnancy, typically in the second trimester. Often, patients will have no symptoms at all and feel completely healthy, which is why regular prenatal testing is important. Left untreated, gestational diabetes may lead to complications for both mother and baby, such as high birth weight and more challenges during delivery.

A person with gestational diabetes may feel thirstier, shaky and have to urinate more often, but in pregnant people, that is a common way to feel. A family history of diabetes is a key risk factor.

Between the 24th and 28th week of pregnancy, a pregnant person takes an oral glucose tolerance test to see if they have gestational diabetes.