About diabetes, type 2

What is diabetes, type 2?

Type 2 diabetes is an impairment in the way the body regulates and uses sugar (glucose) as a fuel. This long-term (chronic) condition results in too much sugar circulating in the bloodstream. Eventually, high blood sugar levels can lead to disorders of the circulatory, nervous and immune systems.

In type 2 diabetes, there are primarily two interrelated problems at work. Your pancreas does not produce enough insulin — a hormone that regulates the movement of sugar into your cells — and cells respond poorly to insulin and take in less sugar.

Type 2 diabetes used to be known as adult-onset diabetes, but both type 1 and type 2 diabetes can begin during childhood and adulthood. Type 2 is more common in older adults, but the increase in the number of children with obesity has led to more cases of type 2 diabetes in younger people.

There's no cure for type 2 diabetes, but losing weight, eating well and exercising can help you manage the disease. If diet and exercise aren't enough to manage your blood sugar, you may also need diabetes medications or insulin therapy.



What are the symptoms for diabetes, type 2?

Signs and 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 signs and 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 doctor if you notice any signs or symptoms of type 2 diabetes.



What are the causes for diabetes, type 2?

Type 2 diabetes is primarily the result of two interrelated problems:

  • Cells in muscle, fat and the liver become resistant to insulin. Because these cells don't interact in a normal way with insulin, they don't take in enough sugar.
  • The pancreas is unable to produce enough insulin to manage blood sugar levels.

Exactly why this happens is unknown, but being overweight and inactive are key contributing factors.

How insulin works

Insulin is a hormone that comes from the gland situated behind and below the stomach (pancreas). Insulin regulates how the body uses sugar in the following ways:

  • Sugar in the bloodstream triggers the pancreas to secrete insulin.
  • Insulin circulates in the bloodstream, enabling sugar to enter your cells.
  • The amount of sugar in your 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 your liver.
  • Glucose is absorbed into the bloodstream, where it enters cells with the help of insulin.
  • Your liver stores and makes glucose.
  • When your glucose levels are low, such as when you haven't eaten in a while, the liver breaks down stored glycogen into glucose to keep your glucose level within a normal range.

In type 2 diabetes, this process doesn't work well. Instead of moving into your cells, sugar builds up in your bloodstream. As blood sugar levels increase, the insulin-producing beta cells in the pancreas release more insulin. Eventually these cells become impaired and can't make enough insulin to meet the body's demands.

In the less common type 1 diabetes, the immune system mistakenly destroys the beta cells, leaving the body with little to no insulin.



What are the treatments for diabetes, type 2?

Management of type 2 diabetes includes:

  • Healthy eating
  • Regular exercise
  • Weight loss
  • 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 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 choices among your food preferences
  • 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 regulating blood sugar levels. Talk to your primary 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. Children should have 60 minutes of moderate to vigorous aerobic exercise daily.

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 two to three sessions of resistance exercise each week. Children should engage in activities that build strength and flexibility at least three days a week. This can include resistance exercises, sports and climbing on playground equipment.

Limit inactivity. Breaking up long bouts 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 and disease management.

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 do this 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 your blood. You should 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 your skin. Information can be transmitted to a mobile device such as your 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 doctor may prescribe diabetes medications that help lower insulin levels or insulin therapy. Drug treatments for type 2 diabetes include the following.

Metformin (Fortamet, Glumetza, others) is generally the first medication prescribed for type 2 diabetes. It works primarily by lowering glucose production in the liver and improving your body's sensitivity to insulin so that your body 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 your body secrete more insulin. Examples include glyburide (DiaBeta, Glynase), glipizide (Glucotrol) 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, and the duration of 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. Examples include rosiglitazone (Avandia) and pioglitazone (Actos). Possible side effects include:

  • Risk of congestive heart failure
  • Risk of bladder cancer (pioglitazone)
  • Risk of bone fractures
  • High cholesterol (rosiglitazone)
  • 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), liraglutide (Saxenda, Victoza) and semaglutide (Rybelsus, Ozempic). Possible side effects include:

  • Risk of pancreatitis
  • Nausea
  • Vomiting
  • Diarrhea

SGLT2 inhibitors affect the blood-filtering functions in your kidneys by inhibiting the return of glucose to the bloodstream. As a result, glucose is excreted in the urine. These drugs 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:

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

Other medications your doctor might prescribe in addition to diabetes medications include blood pressure and cholesterol-lowering medications, 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 medications.

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 might be used at mealtime.

Your doctor will determine what type of insulin is appropriate 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 (hypoglycemia), diabetic ketoacidosis and high triglycerides.

Weight-loss surgery

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

Weight-loss surgery is only one part of an overall treatment plan. Your treatment will also include 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 comorbid 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 include nutritional deficiencies and osteoporosis.

Pregnancy

Women with type 2 diabetes will likely need to change their treatment plans and adhere to diets that carefully controls carbohydrate intake. Many women will need insulin therapy during pregnancy and may need to discontinue other treatments, such as blood pressure medications.

There is an increased risk during pregnancy of developing diabetic retinopathy or a worsening of the condition. If you are pregnant or planning a pregnancy, visit an ophthalmologist during each trimester of your pregnancy, one year postpartum or as advised.

Signs of trouble

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

High blood sugar (hyperglycemia). Eating certain foods or too much food, being sick, or not taking medications at the right time can cause high blood sugar. Signs and 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. Signs and 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 medications — including the diabetes medications called SGLT2 inhibitors.

Although diabetic ketoacidosis is usually less severe in type 2 diabetes, the toxicity of the acids can be life-threatening. In addition to the signs and symptoms of hypoglycemia, such as frequent urination and increased thirst, ketoacidosis may result in:

  • 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 (hypoglycemia). Your blood sugar level can drop for many reasons, including skipping a meal, unintentionally taking more medication than usual or being more physical activity than usual. Signs and symptoms include:

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

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 or another source of sugar. Retest your blood in 15 minutes. If levels are not at your target, repeat the sugar intake. Eat a meal after levels return to normal.

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

More Information
  • Medications for type 2 diabetes
  • GLP-1 agonists: Diabetes drugs and weight loss
  • Bariatric surgery
  • Endoscopic sleeve gastroplasty
  • Gastric bypass (Roux-en-Y)
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What are the risk factors for diabetes, type 2?

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

  • Weight. Being overweight or obese is a main risk.
  • Fat distribution. Storing fat mainly in your abdomen — rather than your hips and thighs — indicates a greater risk. Your risk of type 2 diabetes rises if you're a man with a waist circumference above 40 inches (101.6 centimeters) or a woman with a measurement above 35 inches (88.9 centimeters).
  • Inactivity. The less active you are, the greater your risk. Physical activity helps control your weight, uses up glucose as energy and makes your cells more sensitive to insulin.
  • Family history. The risk of type 2 diabetes increases if your 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 as you get older, especially after age 45.
  • Prediabetes. Prediabetes is a condition in which your 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. Your risk of developing type 2 diabetes increases if you developed gestational diabetes when you were pregnant or if you gave birth to a baby weighing more than 9 pounds (4 kilograms).
  • Polycystic ovary syndrome. Having polycystic ovary syndrome — a common condition characterized by irregular menstrual periods, excess hair growth and obesity — increases the risk of diabetes
  • Areas of darkened skin, usually in the armpits and neck. This condition often indicates insulin resistance.



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