Diabetes is a disease that occurs when your blood glucose, also called blood sugar, is too high. Blood glucose is your main source of energy and comes from the food you eat. Insulin, a hormone made by the pancreas, helps glucose from food get into your cells to be used for energy. Sometimes your body doesn’t make enough—or any—insulin or doesn’t use insulin well. Glucose then stays in your blood and doesn’t reach your cells.
Over time, having too much glucose in your blood can cause health problems. Although diabetes has no cure, you can take steps to manage your diabetes and stay healthy.
Sometimes people call diabetes “a touch of sugar” or “borderline diabetes.” These terms suggest that someone doesn’t really have diabetes or has a less serious case, but every case of diabetes is serious.
What are the different types of Diabetes?
The most common types of diabetes are type 1, type 2, and gestational diabetes.
Type 1 Diabetes
If you have type 1 diabetes, your body does not make insulin. Your immune system attacks and destroys the cells in your pancreas that make insulin. Type 1 diabetes is usually diagnosed in children and young adults, although it can appear at any age. People with type 1 diabetes need to take insulin every day to stay alive.
Type 2 Diabetes
If you have type 2 diabetes, your body does not make or use insulin well. You can develop type 2 diabetes at any age, even during childhood. However, this type of diabetes occurs most often in middle-aged and older people. Type 2 is the most common type of diabetes.
Gestational diabetes develops in some women when they are pregnant. Most of the time, this type of diabetes goes away after the baby is born. However, if you’ve had gestational diabetes, you have a greater chance of developing type 2 diabetes later in life. Sometimes diabetes diagnosed during pregnancy is actually type 2 diabetes.
Who is more likely to develop type 2 diabetes?
You are more likely to develop type 2 diabetes if you are age 45 or older, have a family history of diabetes, or are overweight. Physical inactivity, race, and certain health problems such as high blood pressure also affect your chance of developing type 2 diabetes. You are also more likely to develop type 2 diabetes if you have prediabetes or had gestational diabetes when you were pregnant. Learn more about risk factors for type 2 diabetes.
What health problems can people with diabetes develop?
Over time, high blood glucose leads to problems such as
- Heart disease
- Kidney disease
- Eye problems
- Dental disease
- Nerve damage
- Foot problems
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.
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:
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.
Management of type 2 diabetes include:
- 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.
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:
- Whole grains
You'll also need to eat fewer animal products, refined carbohydrates and sweets.
Low glycaemic 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 fibre.
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.
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.
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. 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.
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.
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.