Diabetes Mellitus

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Diabetes Mellitus
Signs and Symptoms

There are three main types of diabetes:

Type 1 Diabetes: About 5 to 10 percent of those with diabetes have type 1 diabetes. It's an autoimmune disease, meaning the body's own immune system mistakenly attacks and destroys the insulin-producing cells in the pancreas. Patients with type 1 diabetes have very little or no insulin, and must take insulin everyday. Although the condition can appear at any age, typically it's diagnosed in children and young adults, which is why it was previously called juvenile diabetes.

Type 2 Diabetes: Accounting for 90 to 95 percent of those with diabetes, type 2 is the most common form. Usually, it's diagnosed in adults over age 40 and 80 percent of those with type 2 diabetes are overweight. Because of the increase in obesity, type 2 diabetes is being diagnosed at younger ages, including in children. Initially in type 2 diabetes, insulin is produced, but the insulin doesn't function properly, leading to a condition called insulin resistance. Eventually, most people with type 2 diabetes suffer from decreased insulin production.

Gestational Diabetes: Gestational diabetes develops during pregnancy. It occurs more often in African Americans, Native Americans, Latinos and people with a family history of diabetes. Typically, it disappears after delivery, although the condition is associated with an increased risk of developing diabetes later in life.

If you think that you have diabetes, visit your doctor immediately for a definite diagnosis. Common symptoms include the following:

• Frequent urination
• Excessive thirst
• Unexplained weight loss
• Extreme hunger
• Sudden vision changes
• Tingling or numbness in the hands or feet
• Feeling very tired much of the time
• Very dry skin
• Sores that are slow to heal
• More infections than usual

Some people may experience only a few symptoms that are listed above. About 50 percent of people with type 2 diabetes don't experience any symptoms and don't know they have the disease.

Learn more about our Diabetes Education Online and classes and workshops at the UCSF Diabetes Center.

Reviewed by health care specialists at UCSF Medical Center.

Your doctor will first ask about your medical history and perform a physical examination to check for symptoms of diabetes and high blood sugar. Diabetes usually is diagnosed with the following tests that measure the glucose levels in your blood:

Fasting Plasma Glucose Test: This is the standard test for diagnosing type 1 and type 2 diabetes. You must not eat or drink anything for at least eight hours prior to this simple test in which blood is drawn to check your sugar levels. A diagnosis of diabetes will be made if you have a fasting blood sugar level of 126 milligrams per deciliter or higher on two separate days.

Other Tests: Diabetes also may be diagnosed based on a random high glucose level of 200mg/dl and symptoms of the disease. Your doctor may wish to perform an oral glucose tolerance test, which is the traditional test for diabetes mellitus.