Symptoms of type 2 diabetes often develop slowly. In fact, you can be living with type 2 diabetes for years and not know it. When symptoms are present, they may include:

• Increased thirst.
• Frequent urination.
• Increased hunger.
• Unintended weight loss.
• Fatigue.
• Blurred vision.
• Slow-healing sores.
• Frequent infections.
• Numbness or tingling in the hands or feet.
• Areas of darkened skin, usually in the armpits and neck.

When to see a doctor

See your health care provider if you notice any symptoms of type 2 diabetes.

Type 2 diabetes is mainly the result of two problems:

• Cells in muscle, fat and the liver become resistant to insulin As a result, the cells don't take in enough sugar.
• The pancreas can't make enough insulin to keep blood sugar levels within a healthy range.

Exactly why this happens is not known. Being overweight and inactive are key contributing factors.

How insulin works

Insulin is a hormone that comes from the pancreas — a gland located behind and below the stomach. Insulin controls how the body uses sugar in the following ways:

• Sugar in the bloodstream triggers the pancreas to release insulin.
• Insulin circulates in the bloodstream, enabling sugar to enter the cells.
• The amount of sugar in the bloodstream drops.
• In response to this drop, the pancreas releases less insulin.

The role of glucose

Glucose — a sugar — is a main source of energy for the cells that make up muscles and other tissues. The use and regulation of glucose includes the following:

• Glucose comes from two major sources: food and the liver.
• Glucose is absorbed into the bloodstream, where it enters cells with the help of insulin.
• The liver stores and makes glucose.
• When glucose levels are low, the liver breaks down stored glycogen into glucose to keep the body's glucose level within a healthy range.

In type 2 diabetes, this process doesn't work well. Instead of moving into the cells, sugar builds up in the blood. As blood sugar levels rise, the pancreas releases more insulin. Eventually the cells in the pancreas that make insulin become damaged and can't make enough insulin to meet the body's needs.

Factors that may increase the risk of type 2 diabetes include:

• Weight. Being overweight or obese is a main risk.
• Fat distribution. Storing fat mainly in the abdomen — rather than the hips and thighs — indicates a greater risk. The risk of type 2 diabetes is higher in men with a waist circumference above 40 inches (101.6 centimeters) and in women with a waist measurement above 35 inches (88.9 centimeters).
• Inactivity. The less active a person is, the greater the risk. Physical activity helps control weight, uses up glucose as energy and makes cells more sensitive to insulin.
• Family history. An individual's risk of type 2 diabetes increases if a parent or sibling has type 2 diabetes.
• Race and ethnicity. Although it's unclear why, people of certain races and ethnicities — including Black, Hispanic, Native American and Asian people, and Pacific Islanders — are more likely to develop type 2 diabetes than white people are.
• Blood lipid levels. An increased risk is associated with low levels of high-density lipoprotein (HDL) cholesterol — the "good" cholesterol — and high levels of triglycerides.
• Age. The risk of type 2 diabetes increases with age, especially after age 35.
• Prediabetes. Prediabetes is a condition in which the blood sugar level is higher than normal, but not high enough to be classified as diabetes. Left untreated, prediabetes often progresses to type 2 diabetes.
• Pregnancy-related risks. The risk of developing type 2 diabetes is higher in people who had gestational diabetes when they were pregnant and in those who gave birth to a baby weighing more than 9 pounds (4 kilograms).
• Polycystic ovary syndrome. Having polycystic ovary syndrome — a condition characterized by irregular menstrual periods, excess hair growth and obesity — increases the risk of diabetes.

Type 2 diabetes affects many major organs, including the heart, blood vessels, nerves, eyes and kidneys. Also, factors that increase the risk of diabetes are risk factors for other serious diseases. Managing diabetes and controlling blood sugar can lower the risk for these complications and other medical conditions, including:

• Heart and blood vessel disease. Diabetes is associated with an increased risk of heart disease, stroke, high blood pressure and narrowing of blood vessels, a condition called atherosclerosis.
• Nerve damage in limbs. This condition is called neuropathy. High blood sugar over time can damage or destroy nerves. That may result in tingling, numbness, burning, pain or eventual loss of feeling that usually begins at the tips of the toes or fingers and gradually spreads upward.
• Other nerve damage. Damage to nerves of the heart can contribute to irregular heart rhythms. Nerve damage in the digestive system can cause problems with nausea, vomiting, diarrhea or constipation. Nerve damage also may cause erectile dysfunction.
• Kidney disease. Diabetes may lead to chronic kidney disease or end-stage kidney disease that can't be reversed. That may require dialysis or a kidney transplant.
• Eye damage. Diabetes increases the risk of serious eye diseases, such as cataracts and glaucoma, and may damage the blood vessels of the retina, potentially leading to blindness.
• Skin conditions. Diabetes may raise the risk of some skin problems, including bacterial and fungal infections.
• Slow healing. Left untreated, cuts and blisters can become serious infections, which may heal poorly. Severe damage might require toe, foot or leg amputation.
• Hearing impairment. Hearing problems are more common in people with diabetes.
• Sleep apnea. Obstructive sleep apnea is common in people living with type 2 diabetes. Obesity may be the main contributing factor to both conditions.
• Dementia. Type 2 diabetes seems to increase the risk of Alzheimer's disease and other disorders that cause dementia. Poor control of blood sugar is linked to a more rapid decline in memory and other thinking skills.

Healthy lifestyle choices can help prevent type 2 diabetes. If you've received a diagnosis of prediabetes, lifestyle changes may slow or stop the progression to diabetes.

A healthy lifestyle includes:

• Eating healthy foods. Choose foods lower in fat and calories and higher in fiber. Focus on fruits, vegetables and whole grains.
• Getting active. Aim for 150 or more minutes a week of moderate to vigorous aerobic activity, such as a brisk walk, bicycling, running or swimming.
• Losing weight. If you are overweight, losing a modest amount of weight and keeping it off may delay the progression from prediabetes to type 2 diabetes. If you have prediabetes, losing 7% to 10% of your body weight may reduce the risk of diabetes.
• Avoiding long stretches of inactivity. Sitting still for long periods of time can increase the risk of type 2 diabetes. Try to get up every 30 minutes and move around for at least a few minutes.

For people with prediabetes, metformin (Fortamet, Glumetza, others), a diabetes medication, may be prescribed to reduce the risk of type 2 diabetes. This is usually prescribed for older adults who are obese and unable to lower blood sugar levels with lifestyle changes.

Type 2 diabetes is usually diagnosed using the glycated hemoglobin (A1C) test. This blood test indicates your average blood sugar level for the past two to three months. Results are interpreted as follows:

• Below 5.7% is normal.
• 5.7% to 6.4% is diagnosed as prediabetes.
• 6.5% or higher on two separate tests indicates diabetes.

If the A1C test isn't available, or if you have certain conditions that interfere with an A1C test, your health care provider may use the following tests to diagnose diabetes:

Random blood sugar test. Blood sugar values are expressed in milligrams of sugar per deciliter (mg/dL) or millimoles of sugar per liter (mmol/L) of blood. Regardless of when you last ate, a level of 200 mg/dL (11.1 mmol/L) or higher suggests diabetes, especially if you also have symptoms of diabetes, such as frequent urination and extreme thirst.

Fasting blood sugar test. A blood sample is taken after you haven't eaten overnight. Results are interpreted as follows:

• Less than 100 mg/dL (5.6 mmol/L) is considered healthy.
• 100 to 125 mg/dL (5.6 to 6.9 mmol/L) is diagnosed as prediabetes.
• 126 mg/dL (7 mmol/L) or higher on two separate tests is diagnosed as diabetes.

Oral glucose tolerance test. This test is less commonly used than the others, except during pregnancy. You'll need to not eat for a certain amount of time and then drink a sugary liquid at your health care provider's office. Blood sugar levels then are tested periodically for two hours. Results are interpreted as follows:

• Less than 140 mg/dL (7.8 mmol/L) after two hours is considered healthy.
• 140 to 199 mg/dL (7.8 mmol/L and 11.0 mmol/L) is diagnosed as prediabetes.
• 200 mg/dL (11.1 mmol/L) or higher after two hours suggests diabetes.

Screening. The American Diabetes Association recommends routine screening with diagnostic tests for type 2 diabetes in all adults age 35 or older and in the following groups:

• People younger than 35 who are overweight or obese and have one or more risk factors associated with diabetes.
• Women who have had gestational diabetes.
• People who have been diagnosed with prediabetes.
• Children who are overweight or obese and who have a family history of type 2 diabetes or other risk factors.

After a diagnosis

If you're diagnosed with diabetes, your health care provider may do other tests to distinguish between type 1 and type 2 diabetes because the two conditions often require different treatments.

Your health care provider will test A1C levels at least two times a year and when there are any changes in treatment. Target A1C goals vary depending on age and other factors. For most people, the American Diabetes Association recommends an A1C level below 7%.

You also receive tests to screen for complications of diabetes and other medical conditions.

Management of type 2 diabetes includes:

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

These steps make it more likely that blood sugar will stay in a healthy range. And they may help to delay or prevent complications.

Healthy eating

There's no specific diabetes diet. However, it's important to center your diet around:

• A regular schedule for meals and healthy snacks.
• Smaller portion sizes.
• More high-fiber foods, such as fruits, nonstarchy vegetables and whole grains.
• Fewer refined grains, starchy vegetables and sweets.
• Modest servings of low-fat dairy, low-fat meats and fish.
• Healthy cooking oils, such as olive oil or canola oil.
• Fewer calories.

Your health care provider may recommend seeing a registered dietitian, who can help you:

• Identify healthy food choices.
• Plan well-balanced, nutritional meals.
• Develop new habits and address barriers to changing habits.
• Monitor carbohydrate intake to keep your blood sugar levels more stable.

Physical activity

Exercise is important for losing weight or maintaining a healthy weight. It also helps with managing blood sugar. Talk to your health care provider before starting or changing your exercise program to ensure that activities are safe for you.

• Aerobic exercise. Choose an aerobic exercise that you enjoy, such as walking, swimming, biking or running. Adults should aim for 30 minutes or more of moderate aerobic exercise on most days of the week, or at least 150 minutes a week.
• Resistance exercise. Resistance exercise increases your strength, balance and ability to perform activities of daily living more easily. Resistance training includes weightlifting, yoga and calisthenics. Adults living with type 2 diabetes should aim for 2 to 3 sessions of resistance exercise each week.
• Limit inactivity. Breaking up long periods of inactivity, such as sitting at the computer, can help control blood sugar levels. Take a few minutes to stand, walk around or do some light activity every 30 minutes.

Weight loss

Weight loss results in better control of blood sugar levels, cholesterol, triglycerides and blood pressure. If you're overweight, you may begin to see improvements in these factors after losing as little as 5% of your body weight. However, the more weight you lose, the greater the benefit to your health. In some cases, losing up to 15% of body weight may be recommended.

Your health care provider or dietitian can help you set appropriate weight-loss goals and encourage lifestyle changes to help you achieve them.

Monitoring your blood sugar

Your health care provider will advise you on how often to check your blood sugar level to make sure you remain within your target range. You may, for example, need to check it once a day and before or after exercise. If you take insulin, you may need to check your blood sugar multiple times a day.

Monitoring is usually done with a small, at-home device called a blood glucose meter, which measures the amount of sugar in a drop of blood. Keep a record of your measurements to share with your health care team.

Continuous glucose monitoring is an electronic system that records glucose levels every few minutes from a sensor placed under the skin. Information can be transmitted to a mobile device such as a phone, and the system can send alerts when levels are too high or too low.

Diabetes medications

If you can't maintain your target blood sugar level with diet and exercise, your health care provider may prescribe diabetes medications that help lower glucose levels, or your provider may suggest insulin therapy. Medicines for type 2 diabetes include the following.

Metformin (Fortamet, Glumetza, others) is generally the first medicine prescribed for type 2 diabetes. It works mainly by lowering glucose production in the liver and improving the body's sensitivity to insulin so it uses insulin more effectively.

Some people experience B-12 deficiency and may need to take supplements. Other possible side effects, which may improve over time, include:

• Nausea.
• Abdominal pain.
• Bloating.
• Diarrhea.

Sulfonylureas help the body secrete more insulin. Examples include glyburide (DiaBeta, Glynase), glipizide (Glucotrol XL) and glimepiride (Amaryl). Possible side effects include:

• Low blood sugar.
• Weight gain.

Glinides stimulate the pancreas to secrete more insulin. They're faster acting than sulfonylureas. But their effect in the body is shorter. Examples include repaglinide and nateglinide. Possible side effects include:

• Low blood sugar.
• Weight gain.

Thiazolidinediones make the body's tissues more sensitive to insulin. An example of this medicine is pioglitazone (Actos). Possible side effects include:

• Risk of congestive heart failure.
• Risk of bladder cancer (pioglitazone).
• Risk of bone fractures.
• Weight gain.

DPP-4 inhibitors help reduce blood sugar levels but tend to have a very modest effect. Examples include sitagliptin (Januvia), saxagliptin (Onglyza) and linagliptin (Tradjenta). Possible side effects include:

• Risk of pancreatitis.
• Joint pain.

GLP-1 receptor agonists are injectable medications that slow digestion and help lower blood sugar levels. Their use is often associated with weight loss, and some may reduce the risk of heart attack and stroke. Examples include exenatide (Byetta, Bydureon Bcise), liraglutide (Saxenda, Victoza) and semaglutide (Rybelsus, Ozempic, Wegovy). Possible side effects include:

• Risk of pancreatitis.
• Nausea.
• Vomiting.
• Diarrhea.

SGLT2 inhibitors affect the blood-filtering functions in the kidneys by blocking the return of glucose to the bloodstream. As a result, glucose is removed in the urine. These medicines may reduce the risk of heart attack and stroke in people with a high risk of those conditions. Examples include canagliflozin (Invokana), dapagliflozin (Farxiga) and empagliflozin (Jardiance). Possible side effects include:

• Vaginal yeast infections.
• Urinary tract infections.
• Low blood pressure.
• High cholesterol.
• Risk of gangrene.
• Risk of bone fractures (canagliflozin).
• Risk of amputation (canagliflozin).

Other medicines your health care provider might prescribe in addition to diabetes medications include blood pressure and cholesterol-lowering medicines, as well as low-dose aspirin, to help prevent heart and blood vessel disease.

Insulin therapy

Some people who have type 2 diabetes need insulin therapy. In the past, insulin therapy was used as a last resort, but today it may be prescribed sooner if blood sugar targets aren't met with lifestyle changes and other medicines.

Different types of insulin vary on how quickly they begin to work and how long they have an effect. Long-acting insulin, for example, is designed to work overnight or throughout the day to keep blood sugar levels stable. Short-acting insulin generally is used at mealtime.

Your health care provider will determine what type of insulin is right for you and when you should take it. Your insulin type, dosage and schedule may change depending on how stable your blood sugar levels are. Most types of insulin are taken by injection.

Side effects of insulin include the risk of low blood sugar — a condition called hypoglycemia — diabetic ketoacidosis and high triglycerides.

Weight-loss surgery

Weight-loss surgery changes the shape and function of the digestive system. This surgery may help you lose weight and manage type 2 diabetes and other conditions related to obesity. There are several surgical procedures. All of them help people lose weight by limiting how much food they can eat. Some procedures also limit the amount of nutrients the body can absorb.

Weight-loss surgery is only one part of an overall treatment plan. Treatment also includes diet and nutritional supplement guidelines, exercise and mental health care.

Generally, weight-loss surgery may be an option for adults living with type 2 diabetes who have a body mass index (BMI) of 35 or higher. BMI is a formula that uses weight and height to estimate body fat. Depending on the severity of diabetes or the presence of other medical conditions, surgery may be an option for someone with a BMI lower than 35.

Weight-loss surgery requires a lifelong commitment to lifestyle changes. Long-term side effects may include nutritional deficiencies and osteoporosis.

Pregnancy

People living with type 2 diabetes often need to change their treatment plan during pregnancy and follow a diet that controls carbohydrates. Many people need insulin therapy during pregnancy. They also may need to stop other treatments, such as blood pressure medicines.

There is an increased risk during pregnancy of developing a condition that affects the eyes called diabetic retinopathy. In some cases, this condition may get worse during pregnancy. If you are pregnant, visit an ophthalmologist during each trimester of your pregnancy and one year after you give birth. Or as often as your health care provider suggests.

Signs of trouble

Regularly monitoring your blood sugar levels is important to avoid severe complications. Also, be aware of symptoms that may suggest irregular blood sugar levels and the need for immediate care:

High blood sugar. This condition also is called hyperglycemia. Eating certain foods or too much food, being sick, or not taking medications at the right time can cause high blood sugar. Symptoms include:

• Frequent urination.
• Increased thirst.
• Dry mouth.
• Blurred vision.
• Fatigue.
• Headache.

Hyperglycemic hyperosmolar nonketotic syndrome (HHNS). This life-threatening condition includes a blood sugar reading higher than 600 mg/dL (33.3 mmol/L). HHNS may be more likely if you have an infection, are not taking medicines as prescribed, or take certain steroids or drugs that cause frequent urination. Symptoms include:

• Dry mouth.
• Extreme thirst.
• Drowsiness.
• Confusion.
• Dark urine.
• Seizures.

Diabetic ketoacidosis. Diabetic ketoacidosis occurs when a lack of insulin results in the body breaking down fat for fuel rather than sugar. This results in a buildup of acids called ketones in the bloodstream. Triggers of diabetic ketoacidosis include certain illnesses, pregnancy, trauma and medicines — including the diabetes medicines called SGLT2 inhibitors.

The toxicity of the acids made by diabetic ketoacidosis can be life-threatening. In addition to the symptoms of hyperglycemia, such as frequent urination and increased thirst, ketoacidosis may cause:

• Nausea.
• Vomiting.
• Abdominal pain.
• Shortness of breath.
• Fruity-smelling breath.

Low blood sugar. If your blood sugar level drops below your target range, it's known as low blood sugar. This condition also is called hypoglycemia. Your blood sugar level can drop for many reasons, including skipping a meal, unintentionally taking more medication than usual or being more physically active than usual. Symptoms include:

• Sweating.
• Shakiness.
• Weakness.
• Hunger.
• Irritability.
• Dizziness.
• Headache.
• Blurred vision.
• Heart palpitations.
• Slurred speech.
• Drowsiness.
• Confusion.

If you have symptoms of low blood sugar, drink or eat something that will quickly raise your blood sugar level. Examples include fruit juice, glucose tablets, hard candy or another source of sugar. Retest your blood in 15 minutes. If levels are not at your target, eat or drink another source of sugar. Eat a meal after your blood sugar level returns to normal.

If you lose consciousness, you need to be given an emergency injection of glucagon, a hormone that stimulates the release of sugar into the blood.

Careful management of type 2 diabetes can reduce the 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.
• Work with your team. Establish a relationship with a certified diabetes education specialist, and ask your diabetes treatment team for help when you need it.
• Identify yourself. Wear a necklace or bracelet that says you are living with diabetes, especially if you take insulin or other blood sugar-lowering medicine.
• Schedule a yearly physical exam and regular eye exams. Your diabetes checkups aren't meant to replace regular physicals or routine eye exams.
• Keep your vaccinations up to date. High blood sugar can weaken your immune system. Get a flu shot every year. Your health care provider also may recommend the pneumonia vaccine. 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 19 to 59 years old. Talk to your health care provider about other vaccinations you may need.
• Take care of your teeth. Diabetes may leave you prone to more-serious gum infections. Brush and floss your teeth regularly and schedule recommended dental exams. Contact 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 them with lotion. Check your feet every day for blisters, cuts, sores, redness and swelling. Contact your health care provider 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. Take medication as prescribed.
• If you smoke or use other types of tobacco, ask your health care provider to help you quit. Smoking increases your risk of diabetes complications. Talk to your health care provider about ways to stop using tobacco.
• Use alcohol sparingly. Depending on the type of drink, alcohol may lower or raise blood sugar levels. If you choose to drink alcohol, only do so with a meal. The recommendation is no more than one drink daily for women and no more than two drinks daily for men. Check your blood sugar frequently after drinking alcohol.
• Make healthy sleep a priority. Many people with type 2 diabetes have sleep problems. And not getting enough sleep may make it harder to keep blood sugar levels in a healthy range. If you have trouble sleeping, talk to your health care provider about treatment options.

Many alternative medicine treatments claim to help people living with diabetes. According to the National Center for Complementary and Integrative Health, studies haven't provided enough evidence to recommend any alternative therapies for blood sugar management. Research has shown the following results about popular supplements for type 2 diabetes:

• Chromium supplements have been shown to have few or no benefits. Large doses can result in kidney damage, muscle problems and skin reactions.
• Magnesium supplements have shown benefits for blood sugar control in some but not all studies. Side effects include diarrhea and cramping. Very large doses — more than 5,000 mg a day — can be fatal.
• Cinnamon, in some studies, has lowered fasting glucose levels but not A1C levels. Therefore, there's no evidence of overall improved glucose management.

Talk to your health care provider before starting a dietary supplement or natural remedy. Do not replace your prescribed diabetes medicines with alternative medicines.

Type 2 diabetes is a serious disease, and following your diabetes treatment plan takes commitment. To effectively manage diabetes, you may need a good support network.

Anxiety and depression are common in people living with diabetes. Talking to a counselor or therapist may help you cope with the lifestyle changes and stress that come with a type 2 diabetes diagnosis.

Support groups can be good sources of diabetes education, emotional support and helpful information, such as how to find local resources or where to find carbohydrate counts for a favorite restaurant. If you're interested, your health care provider may be able to recommend a group in your area.

You can visit the American Diabetes Association website to check out local activities and support groups for people living with type 2 diabetes. The American Diabetes Association also offers online information and online forums where you can chat with others who are living with diabetes. You also can call the organization at 800-DIABETES (800-342-2383).

At your annual wellness visit, your health care provider can screen for diabetes and monitor and treat conditions that increase your risk of diabetes, such as high blood pressure, high cholesterol or a high BMI.

If you are seeing your health care provider because of symptoms that may be related to diabetes, you can prepare for your appointment by being ready to answer the following questions:

• When did your symptoms begin?
• Does anything improve the symptoms or worsen the symptoms?
• What medicines do you take regularly, including dietary supplements and herbal remedies?
• What are your typical daily meals? Do you eat between meals or before bedtime?
• How much alcohol do you drink?
• How much daily exercise do you get?
• Is there a history of diabetes in your family?

If you are diagnosed with diabetes, your health care provider may begin a treatment plan. Or you may be referred to a doctor who specializes in hormonal disorders, called an endocrinologist. Your care team also may include the following specialists:

• Dietitian.
• Certified diabetes education specialist.
• Foot doctor, also called a podiatrist.
• Doctor who specializes in eye care, called an ophthalmologist.

Talk to your health care provider about referrals to other specialists who may be providing care.

Questions for ongoing appointments

Before any appointment with a member of your treatment team, make sure you know whether there are any restrictions, such as not eating or drinking before taking a test. Questions that you should regularly talk about with your health care provider or other members of the team include:

• How often do I need to monitor my blood sugar, and what is my target range?
• What changes in my diet would help me better manage my blood sugar?
• What is the right dosage for prescribed medications?
• When do I take the medications? Do I take them with food?
• How does management of diabetes affect treatment for other conditions? How can I better coordinate treatments or care?
• When do I need to make a follow-up appointment?
• Under what conditions should I call you or seek emergency care?
• Are there brochures or online sources you recommend?
• Are there resources available if I'm having trouble paying for diabetes supplies?

What to expect from your doctor

Your health care provider is likely to ask you questions at your appointments. Those questions may include:

• Do you understand your treatment plan and feel confident you can follow it?
• How are you coping with diabetes?
• Have you had any low blood sugar?
• Do you know what to do if your blood sugar is too low or too high?
• What's a typical day's diet like?
• Are you exercising? If so, what type of exercise? How often?
• Do you sit for long periods of time?
• What challenges are you experiencing in managing your diabetes?