Diagnosis

To diagnose type 2 diabetes, you'll be given a:

  • Glycated hemoglobin (A1C) test. This blood test indicates your average blood sugar level for the past two to three months. It measures the percentage of blood sugar attached to hemoglobin, the oxygen-carrying protein in red blood cells. The higher your blood sugar levels, the more hemoglobin you'll have with sugar attached. An A1C level of 6.5 percent or higher on two separate tests indicates you have diabetes. A result between 5.7 and 6.4 percent is considered prediabetes, which indicates a high risk of developing diabetes. Normal levels are below 5.7 percent.

If the A1C test isn't available, or if you have certain conditions — such as if you're pregnant or have an uncommon form of hemoglobin (known as a hemoglobin variant) — that can make the A1C test inaccurate, your doctor may use the following tests to diagnose diabetes:

  • Random blood sugar test. A blood sample will be taken at a random time. Blood sugar values are expressed in milligrams per deciliter (mg/dL) or millimoles per liter (mmol/L). Regardless of when you last ate, a random blood sugar level of 200 mg/dL (11.1 mmol/L) or higher suggests diabetes, especially when coupled with any of the signs and symptoms of diabetes, such as frequent urination and extreme thirst.
  • Fasting blood sugar test. A blood sample will be taken after an overnight fast. A fasting blood sugar level less than 100 mg/dL (5.6 mmol/L) is normal. A fasting blood sugar level from 100 to 125 mg/dL (5.6 to 6.9 mmol/L) is considered prediabetes. If it's 126 mg/dL (7 mmol/L) or higher on two separate tests, you have diabetes.
  • Oral glucose tolerance test. For this test, you fast overnight, and the fasting blood sugar level is measured. Then you drink a sugary liquid, and blood sugar levels are tested periodically for the next two hours.

    A blood sugar level less than 140 mg/dL (7.8 mmol/L) is normal. A reading between 140 and 199 mg/dL (7.8 mmol/L and 11.0 mmol/L) indicates prediabetes. A reading of 200 mg/dL (11.1 mmol/L) or higher after two hours may indicate diabetes.

The American Diabetes Association recommends routine screening for type 2 diabetes beginning at age 45, especially if you're overweight. If the results are normal, repeat the test every three years. If the results are borderline, ask your doctor when to come back for another test.

Screening is also recommended for people who are under 45 and overweight if there are other heart disease or diabetes risk factors present, such as a sedentary lifestyle, a family history of type 2 diabetes, a personal history of gestational diabetes or blood pressure above 140/90 millimeters of mercury (mm Hg).

If you're diagnosed with diabetes, the doctor may do other tests to distinguish between type 1 and type 2 diabetes — since the two conditions often require different treatments.

After the diagnosis

A1C levels need to be checked between two and four times a year. Your target A1C goal may vary depending on your age and other factors. However, for most people, the American Diabetes Association recommends an A1C level below 7 percent. Ask your doctor what your A1C target is.

Compared with repeated daily blood sugar tests, the A1C test is a better indicator of how well your diabetes treatment plan is working. An elevated A1C level may signal the need for a change in your medication, meal plan or activity level.

In addition to the A1C test, your doctor will take blood and urine samples periodically to check your cholesterol levels, thyroid function, liver function and kidney function. The doctor will also assess your blood pressure. Regular eye and foot exams also are important.

Treatment

Management of type 2 diabetes includes:

  • Healthy eating
  • Regular exercise
  • Possibly, diabetes medication or insulin therapy
  • Blood sugar monitoring

These steps will help keep your blood sugar level closer to normal, which can delay or prevent complications.

Healthy eating

Contrary to popular perception, there's no specific diabetes diet. However, it's important to center your diet on these high-fiber, low-fat foods:

  • Fruits
  • Vegetables
  • Whole grains

You'll also need to eat fewer animal products, refined carbohydrates and sweets.

Low glycemic index foods also may be helpful. The glycemic index is a measure of how quickly a food causes a rise in your blood sugar. Foods with a high glycemic index raise your blood sugar quickly. Low glycemic index foods may help you achieve a more stable blood sugar. Foods with a low glycemic index typically are foods that are higher in fiber.

A registered dietitian can help you put together a meal plan that fits your health goals, food preferences and lifestyle. He or she can also teach you how to monitor your carbohydrate intake and let you know about how many carbohydrates you need to eat with your meals and snacks to keep your blood sugar levels more stable.

Physical activity

Everyone needs regular aerobic exercise, and people who have type 2 diabetes are no exception. Get your doctor's OK before you start an exercise program. Then choose activities you enjoy, such as walking, swimming and biking. What's most important is making physical activity part of your daily routine.

Aim for at least 30 minutes of aerobic exercise five days of the week. Stretching and strength training exercises are important, too. If you haven't been active for a while, start slowly and build up gradually.

A combination of exercises — aerobic exercises, such as walking or dancing on most days, combined with resistance training, such as weightlifting or yoga twice a week — often helps control blood sugar more effectively than either type of exercise alone.

Remember that physical activity lowers blood sugar. Check your blood sugar level before any activity. You might need to eat a snack before exercising to help prevent low blood sugar if you take diabetes medications that lower your blood sugar.

Monitoring your blood sugar

Depending on your treatment plan, you may need to check and record your blood sugar level every now and then or, if you're on insulin, multiple times a day. Ask your doctor how often he or she wants you to check your blood sugar. Careful monitoring is the only way to make sure that your blood sugar level remains within your target range.

Sometimes, blood sugar levels can be unpredictable. With help from your diabetes treatment team, you'll learn how your blood sugar level changes in response to food, exercise, alcohol, illness and medication.

Diabetes medications and insulin therapy

Some people who have type 2 diabetes can achieve their target blood sugar levels with diet and exercise alone, but many also need diabetes medications or insulin therapy. The decision about which medications are best depends on many factors, including your blood sugar level and any other health problems you have. Your doctor might even combine drugs from different classes to help you control your blood sugar in several different ways.

Examples of possible treatments for type 2 diabetes include:

  • Metformin (Glucophage, Glumetza, others). Generally, metformin is the first medication prescribed for type 2 diabetes. It works by improving the sensitivity of your body tissues to insulin so that your body uses insulin more effectively.

    Metformin also lowers glucose production in the liver. Metformin may not lower blood sugar enough on its own. Your doctor will also recommend lifestyle changes, such as losing weight and becoming more active.

    Nausea and diarrhea are possible side effects of metformin. These side effects usually go away as your body gets used to the medicine. If metformin and lifestyles changes aren't enough to control your blood sugar level, other oral or injected medications can be added.

  • Sulfonylureas. These medications help your body secrete more insulin. Examples of medications in this class include glyburide (DiaBeta, Glynase), glipizide (Glucotrol) and glimepiride (Amaryl). Possible side effects include low blood sugar and weight gain.
  • Meglitinides. These medications work like sulfonylureas by stimulating the pancreas to secrete more insulin, but they're faster acting, and the duration of their effect in the body is shorter. They also have a risk of causing low blood sugar, but this risk is lower than with sulfonylureas.

    Weight gain is a possibility with this class of medications as well. Examples include repaglinide (Prandin) and nateglinide (Starlix).

  • Thiazolidinediones. Like metformin, these medications make the body's tissues more sensitive to insulin. This class of medications has been linked to weight gain and other more-serious side effects, such as an increased risk of heart failure and fractures. Because of these risks, these medications generally aren't a first-choice treatment.

    Rosiglitazone (Avandia) and pioglitazone (Actos) are examples of thiazolidinediones.

  • DPP-4 inhibitors. These medications help reduce blood sugar levels, but tend to have a modest effect. They don't cause weight gain. Examples of these medications are sitagliptin (Januvia), saxagliptin (Onglyza) and linagliptin (Tradjenta).
  • GLP-1 receptor agonists. These medications slow digestion and help lower blood sugar levels, though not as much as sulfonylureas. Their use is often associated with some weight loss. This class of medications isn't recommended for use by itself.

    Exenatide (Byetta) and liraglutide (Victoza) are examples of GLP-1 receptor agonists. Possible side effects include nausea and an increased risk of pancreatitis.

  • SGLT2 inhibitors. These are the newest diabetes drugs on the market. They work by preventing the kidneys from reabsorbing sugar into the blood. Instead, the sugar is excreted in the urine.

    Examples include canagliflozin (Invokana) and dapagliflozin (Farxiga). Side effects may include yeast infections and urinary tract infections, increased urination and hypotension.

  • Insulin therapy. Some people who have type 2 diabetes need insulin therapy as well. In the past, insulin therapy was used as a last resort, but today it's often prescribed sooner because of its benefits.

    Because normal digestion interferes with insulin taken by mouth, insulin must be injected. Depending on your needs, your doctor may prescribe a mixture of insulin types to use throughout the day and night. Often, people with type 2 diabetes start insulin use with one long-acting shot at night.

    Insulin injections involve using a fine needle and syringe or an insulin pen injector — a device that looks similar to an ink pen, except the cartridge is filled with insulin.

    There are many types of insulin, and they each work in a different way. Options include:

    • Insulin glulisine (Apidra)
    • Insulin lispro (Humalog)
    • Insulin aspart (Novolog)
    • Insulin glargine (Lantus)
    • Insulin detemir (Levemir)
    • Insulin isophane (Humulin N, Novolin N)

Discuss the pros and cons of different drugs with your doctor. Together you can decide which medication is best for you after considering many factors, including costs and other aspects of your health.

In addition to diabetes medications, your doctor might prescribe low-dose aspirin therapy as well as blood pressure and cholesterol-lowering medications to help prevent heart and blood vessel disease.

Bariatric surgery

If you have type 2 diabetes and your body mass index (BMI) is greater than 35, you may be a candidate for weight-loss surgery (bariatric surgery). Blood sugar levels return to normal in 55 to 95 percent of people with diabetes, depending on the procedure performed. Surgeries that bypass a portion of the small intestine have more of an effect on blood sugar levels than do other weight-loss surgeries.

Drawbacks to the surgery include its high cost, and there are risks involved, including a risk of death. Additionally, drastic lifestyle changes are required and long-term complications may include nutritional deficiencies and osteoporosis.

Pregnancy

Women with type 2 diabetes may need to alter their treatment during pregnancy. Many women will require insulin therapy during pregnancy. Cholesterol-lowering medications and some blood pressure drugs can't be used during pregnancy.

If you have signs of diabetic retinopathy, it may worsen during pregnancy. Visit your ophthalmologist during the first trimester of your pregnancy and at one year postpartum.

Signs of trouble

Because so many factors can affect your blood sugar, problems sometimes arise that require immediate care, such as:

  • High blood sugar (hyperglycemia). Your blood sugar level can rise for many reasons, including eating too much, being sick or not taking enough glucose-lowering medication. Check your blood sugar level often, and watch for signs and symptoms of high blood sugar — frequent urination, increased thirst, dry mouth, blurred vision, fatigue and nausea. If you have hyperglycemia, you'll need to adjust your meal plan, medications or both.
  • Hyperglycemic hyperosmolar nonketotic syndrome (HHNS). Signs and symptoms of this life-threatening condition include a blood sugar reading higher than 600 mg/dL (33.3 mmol/L), dry mouth, extreme thirst, fever greater than 101 F (38 C), drowsiness, confusion, vision loss, hallucinations and dark urine. Your blood sugar monitor may not be able to give you an exact reading at such high levels and may instead just read "high."

    HHNS is caused by sky-high blood sugar that turns blood thick and syrupy. It tends to be more common in older people with type 2 diabetes, and it's often preceded by an illness or infection. HHNS usually develops over days or weeks. Call your doctor or seek immediate medical care if you have signs or symptoms of this condition.

  • Increased ketones in your urine (diabetic ketoacidosis). If your cells are starved for energy, your body may begin to break down fat. This produces toxic acids known as ketones.

    Watch for thirst or a very dry mouth, frequent urination, vomiting, shortness of breath, fatigue and fruity-smelling breath. You can check your urine for excess ketones with an over-the-counter ketones test kit. If you have excess ketones in your urine, consult your doctor right away or seek emergency care. This condition is more common in people with type 1 diabetes but can sometimes occur in people with type 2 diabetes.

  • Low blood sugar (hypoglycemia). If your blood sugar level drops below your target range, it's known as low blood sugar (hypoglycemia). Your blood sugar level can drop for many reasons, including skipping a meal, inadvertently taking more medication than usual or getting more physical activity than normal. Low blood sugar is most likely if you take glucose-lowering medications that promote the secretion of insulin or if you're taking insulin.

    Check your blood sugar level regularly, and watch for signs and symptoms of low blood sugar — sweating, shakiness, weakness, hunger, dizziness, headache, blurred vision, heart palpitations, slurred speech, drowsiness, confusion and seizures.

    If you develop hypoglycemia during the night, you might wake with sweat-soaked pajamas or a headache. Due to a natural rebound effect, nighttime hypoglycemia might cause an unusually high blood sugar reading first thing in the morning.

    If you have signs or symptoms of low blood sugar, drink or eat something that will quickly raise your blood sugar level — fruit juice, glucose tablets, hard candy, regular (not diet) soda or another source of sugar. Retest in 15 minutes to be sure your blood glucose levels have normalized.

    If they haven't, treat again and retest in another 15 minutes. If you lose consciousness, a family member or close contact may need to give you an emergency injection of glucagon, a hormone that stimulates the release of sugar into the blood.

Clinical trials

Explore Mayo Clinic studies testing new treatments, interventions and tests as a means to prevent, detect, treat or manage this disease.

Lifestyle and home remedies

Careful management of type 2 diabetes can reduce your risk of serious — even life-threatening — complications. Consider these tips:

  • Commit to managing your diabetes. Learn all you can about type 2 diabetes. Make healthy eating and physical activity part of your daily routine. Establish a relationship with a diabetes educator, and ask your diabetes treatment team for help when you need it.
  • Schedule a yearly physical exam and regular eye exams. Your regular diabetes checkups aren't meant to replace regular physicals or routine eye exams. During the physical, your doctor will look for any diabetes-related complications, as well as screen for other medical problems. Your eye care specialist will check for signs of retinal damage, cataracts and glaucoma.
  • Identify yourself. Wear a necklace or bracelet that says you have diabetes.
  • Keep your immunizations up to date. High blood sugar can weaken your immune system. Get a flu shot every year, and your doctor will likely recommend the pneumonia vaccine, as well. The Centers for Disease Control and Prevention (CDC) also recommends the hepatitis B vaccination if you haven't previously received this vaccine and you're an adult age 19 to 59 with type 1 or type 2 diabetes. The CDC advises vaccination as soon as possible after diagnosis with type 1 or type 2 diabetes. If you are age 60 or older, have diabetes and haven't previously received the vaccine, talk to your doctor about whether it's right for you.
  • Take care of your teeth. Diabetes may leave you prone to more-serious gum infections. Brush your teeth at least twice a day, floss your teeth once a day and schedule regular dental exams. Consult your dentist right away if your gums bleed or look red or swollen.
  • Pay attention to your feet. Wash your feet daily in lukewarm water. Dry them gently, especially between the toes, and moisturize with lotion. Check your feet every day for blisters, cuts, sores, redness and swelling. Consult your doctor if you have a sore or other foot problem that isn't healing.
  • Keep your blood pressure and cholesterol under control. Eating healthy foods and exercising regularly can go a long way toward controlling high blood pressure and cholesterol. Medication also may be needed.
  • If you smoke or use other types of tobacco, ask your doctor to help you quit. Smoking increases your risk of various diabetes complications. Talk to your doctor about ways to stop smoking or to stop using other types of tobacco.
  • If you drink alcohol, do so responsibly. Alcohol, as well as drink mixers, can cause either high or low blood sugar, depending on how much you drink and if you eat at the same time. If you choose to drink, do so in moderation and always with a meal.

    The recommendation is no more than one drink daily for women, no more than two drinks daily for men age 65 and younger, and one drink a day for men over 65. If you're on insulin or other medications that lower your blood sugar, check your blood sugar before you go to sleep to make sure you're at a safe level.

Alternative medicine

Numerous alternative medicine substances have been shown to improve insulin sensitivity in some studies, while other studies fail to find any benefit for blood sugar control or in lowering A1C levels. Because of the conflicting findings, no alternative therapies are recommended to help with blood sugar management.

If you decide to try an alternative therapy, don't stop taking the medications that your doctor has prescribed. Be sure to discuss the use of any of these therapies with your doctor to make sure that they won't cause adverse reactions or interact with your medications.

No treatments — alternative or conventional — can cure diabetes. So it's critical that people who are using insulin therapy for diabetes don't stop using insulin unless directed to do so by their physicians.

Coping and support

Type 2 diabetes is a serious disease, and following your diabetes treatment plan takes round-the-clock commitment. But your efforts are worthwhile because following your treatment plan can reduce your risk of complications.

Talking to a counselor or therapist may help you cope with the lifestyle changes that come with a type 2 diabetes diagnosis. You may find encouragement and understanding in a type 2 diabetes support group. Although support groups aren't for everyone, they can be good sources of information. Group members often know about the latest treatments and tend to share their own experiences or helpful information, such as where to find carbohydrate counts for your favorite takeout restaurant. If you're interested, your doctor may be able to recommend a group in your area.

Or, you can visit the American Diabetes Association to check out local activities and support groups for people with type 2 diabetes. The American Diabetes Association also offers online information and online forums where you can chat with others who have diabetes. The phone number is 800-DIABETES (800-342-2383).

Preparing for your appointment

Your primary care doctor will probably diagnose your type 2 diabetes. He or she may continue to treat your diabetes or may refer you to a doctor who specializes in hormonal disorders (endocrinologist). Your health care team also may include:

  • Dietitian
  • Certified diabetes educator
  • Foot doctor (podiatrist)
  • Doctor who specializes in eye care (ophthalmologist)

If your blood sugar levels are very high, your doctor may send you to the hospital for treatment.

Whenever you can, it's a good idea to prepare for appointments with your health care team. Here's some information to help you get ready for your appointment and know what to expect from your doctor.

What you can do

  • Be aware of any pre-appointment restrictions. You may need to refrain from eating or drinking anything but water for eight hours for a fasting glucose test or four hours for a pre-meal test. When you're making an appointment, ask if you should fast.
  • Write down any symptoms you're experiencing, including any that may seem unrelated to your diabetes.
  • Bring a notebook and a pen or pencil (or your laptop computer or tablet) to keep track of important information.
  • Write down questions to ask your doctor.

Preparing a list of questions can help you make the most of your time with your doctor. For type 2 diabetes, some basic questions to ask include:

Glucose monitoring

  • How often do I need to monitor my blood sugar?
  • What is my goal range?
  • How can I use the information from glucose monitoring to better manage my diabetes?

Lifestyle changes

  • What changes do I need to make to my diet?
  • How can I learn about counting carbohydrates in foods?
  • Should I see a dietitian to help with meal planning?
  • How much exercise should I get each day?

Medications

  • Will I need to take medicine? If so, what kind and how much?
  • Do I need to take the medicine at a particular time of the day?
  • Do I need to take insulin?
  • I have other medical problems. How can I best manage these conditions together?

Complications

  • What are the signs and symptoms of low blood sugar?
  • How do I treat low blood sugar?
  • What are the signs and symptoms of high blood sugar?
  • When should I test for ketones, and how do I do it?

Medical management

  • How often do I need to be monitored for diabetes complications? What specialists do I need to see?
  • Are there resources available if I'm having trouble paying for diabetes supplies?
  • Are there brochures or other printed material that I can take with me? What websites do you recommend?

What to expect from your doctor

Your doctor is likely to ask you a number of questions, including:

  • Do you understand your treatment plan and feel confident you can follow it?
  • How are you coping with diabetes?
  • Have you experienced any low blood sugar?
  • What's a typical day's diet like?
  • Are you exercising? If so, what type of exercise? How often?
  • What challenges are you experiencing in managing your diabetes?

What you can do in the meantime

If your blood sugar is consistently out of your target range, or if you're not sure what to do in a certain situation, contact your doctor or diabetes educator.

Oct. 06, 2017
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