What is Diabetes?
Diabetes Mellitus refers to a group of diseases that affect how your body uses blood glucose, commonly called blood sugar. Glucose is vital to your health because it’s an important source of energy for the cells that make up your muscles and tissues. It’s also your brain’s main source of fuel.
If you have diabetes, no matter what type, it means you have too much glucose in your blood, although the reasons may differ. Too much glucose can lead to serious health problems. Chronic diabetes conditions include type 1 diabetes and type 2 diabetes. Potentially reversible diabetes conditions include prediabetes — when your blood sugar levels are higher than normal, but not high enough to be classified as diabetes — and gestational diabetes, which occurs during pregnancy but may resolve after the baby is delivered.
Diabetes symptoms vary depending on how much your blood sugar is elevated. Some people, especially those with pre-diabetes or type 2 diabetes, may not experience symptoms initially. In type 1 diabetes, symptoms tend to come on quickly and be more severe. Some of the signs and symptoms of type 1 and type 2 diabetes include:
- Increased thirst
- Frequent urination
- Extreme hunger
- Unexplained weight loss
- Presence of ketones in the urine (ketones are a byproduct of the breakdown of muscle and fat that happens when there’s not enough insulin)
- Blurred vision
- Slow-healing sores
- High blood pressure
- Frequent infections, such as gums or skin infections and vaginal or bladder infections
Although type 1 diabetes can develop at any age, it typically appears during childhood or adolescence. Type 2 diabetes, the more common type, can develop at any age and is often preventable.
When to seek medical attention
- If you suspect you or your child may have diabetes. If you notice any possible diabetes symptoms, contact your doctor. The earlier the condition is diagnosed, the sooner treatment can begin.
- If you’ve already been diagnosed with diabetes. After you receive your diagnosis, you’ll need close medical follow-up until your blood sugar levels stabilize.
Accu-check or finger prick to test glucose levels
Blood Test to measure glucose levels
Hemoglobin A1c test measures sugar over the past 90 days
Urine Test for sugar levels
How insulin works Insulin is a hormone that comes from the pancreas, a gland situated behind and below the stomach.
- The pancreas secretes insulin into the bloodstream.
- The insulin circulates, enabling sugar to enter your cells.
- Insulin lowers the amount of sugar in your bloodstream.
- As your blood sugar level drops, so does the secretion of insulin from your pancreas.
The role of glucose Glucose — a sugar — is a main source of energy for the cells that make up muscles and other tissues.
- Glucose comes from two major sources: food and your liver.
- Sugar is absorbed into the bloodstream, where it enters cells with the help of insulin.
- Your liver stores and makes glucose.
- When your insulin levels are low, such as when you haven’t eaten in a while, the liver metabolizes stored glycogen into glucose to keep your glucose level within a normal range.
Causes of type 1 diabetes In type 1 diabetes, your immune system — which normally fights harmful bacteria or viruses — attacks and destroys your insulin-producing cells in the pancreas. This leaves you with little or no insulin. Instead of being transported into your cells, sugar builds up in your bloodstream. Type 1 is thought to be caused by a combination of genetic susceptibility and environmental factors, though exactly what many of those factors are is still unclear.
Causes of prediabetes and type 2 diabetes In prediabetes — which can lead to type 2 diabetes — and in type 2 diabetes, your cells become resistant to the action of insulin, and your pancreas is unable to make enough insulin to overcome this resistance. Instead of moving into your cells where it’s needed for energy, sugar builds up in your bloodstream. Exactly why this happens is uncertain, although as in type 1 diabetes, it’s believed that genetic and environmental factors play a role in the development of type 2. Being overweight is strongly linked to the development of type 2 diabetes, but not everyone with type 2 is overweight.
Causes of gestational diabetes During pregnancy, the placenta produces hormones to sustain your pregnancy. These hormones make your cells more resistant to insulin. As your placenta grows larger in the second and third trimesters, it secretes more of these hormones — making it even harder for insulin to do its job.
Normally, your pancreas responds by producing enough extra insulin to overcome this resistance. But sometimes your pancreas can’t keep up. When this happens, too little glucose gets into your cells and too much stays in your blood. This is gestational diabetes.
Risk factors for diabetes depend on the type of diabetes.
Risk factors for type 1 diabetes
Although the exact cause of type 1 diabetes is unknown, genetic factors likely play a role. Your risk of developing type 1 diabetes increases if you have a parent or sibling who has type 1 diabetes. Environmental factors, such as exposure to a viral illness, also likely play some role in type 1 diabetes. Other factors that may increase your risk include:
- The presence of damaging immune system cells that make auto-antibodies. Sometimes family members of people with type 1 diabetes are tested for the presence of diabetes auto-antibodies. If you have these auto-antibodies, you have an increased risk of developing type 1 diabetes. But, not everyone who has these auto-antibodies develops type 1.
- Dietary factors. A number of dietary factors have been linked to an increased risk of type 1 diabetes, such as low vitamin D consumption; early exposure to cow’s milk or cow’s milk formula; or exposure to cereals before 4 months of age. However, none of these factors has been shown to cause type 1 diabetes.
- Race. Type 1 diabetes is more common in whites than in other races.
- Geography Certain countries, such as Finland and Sweden, have higher rates of type 1 diabetes.
Risk factors for pre-diabetes and type 2 diabetes
Researchers don’t fully understand why some people develop pre-diabetes and type 2 diabetes and others don’t. It’s clear that certain factors increase the risk, however, including:
- Weight. The more fatty tissue you have, the more resistant your cells become to insulin.
- Inactivity. The less active you are, the greater your risk. Physical activity helps you control your weight, uses up glucose as energy and makes your cells more sensitive to insulin. Exercising less than three times a week may increase your risk of type 2 diabetes.
- Family history. Your risk increases if a parent or sibling has type 2 diabetes.
- Race. Although it’s unclear why, people of certain races — including blacks, Hispanics, American Indians and Asians — are at higher risk.
- Age. Your risk increases as you get older. This may be because you tend to exercise less, lose muscle mass and gain weight as you age. But type 2 diabetes is also increasing dramatically among children, adolescents and younger adults.
- Gestational diabetes. If you developed gestational diabetes when you were pregnant, your risk of developing prediabetes and type 2 diabetes later increases. If you gave birth to a baby weighing more than 9 pounds (4 kilograms), you’re also at risk of type 2 diabetes.
- Polycystic ovary syndrome. For women, having polycystic ovary syndrome — a common condition characterized by irregular menstrual periods, excess hair growth and obesity — increases the risk of diabetes.
- High blood pressure. Having blood pressure over 140/90mm Hg is linked to an increased risk of type 2 diabetes.
- Abnormal cholesterol levels. If you have low levels of high-density lipoprotein (HDL), or “good,” cholesterol, your risk of type 2 diabetes is higher. Low levels of HDL are defined as below 35 mg/dL.
- High levels of triglycerides. Triglycerides are a fat carried in the blood. If your triglyceride levels are above 250 mg/dL, your risk of diabetes increases.
Risk factors for gestational diabetes Any pregnant woman can develop gestational diabetes, but some women are at greater risk than are others. Risk factors for gestational diabetes include:
- Age. Women older than age 25 are at increased risk.
- Family or personal history. Your risk increases if you have prediabetes — a precursor to type 2 diabetes — or if a close family member, such as a parent or sibling, has type 2 diabetes. You’re also at greater risk if you had gestational diabetes during a previous pregnancy, if you delivered a very large baby or if you had an unexplained stillbirth.
- Weight. Being overweight before pregnancy increases your risk.
- Race. For reasons that aren’t clear, women who are black, Hispanic, American Indian or Asian are more likely to develop gestational diabetes.
Long-term complications of diabetes develop gradually. The longer you have diabetes — and the less controlled your blood sugar — the higher the risk of complications. Eventually, diabetes complications may be disabling or even life-threatening. Possible complications include:
- Cardiovascular disease. Diabetes dramatically increases the risk of various cardiovascular problems, including coronary artery disease with chest pain (angina), heart attack, stroke and narrowing of arteries (atherosclerosis). If you have diabetes, you are more likely to have heart disease or stroke.
- Nerve damage (neuropathy). Excess sugar can injure the walls of the tiny blood vessels (capillaries) that nourish your nerves, especially in the legs. This can cause tingling, numbness, burning or pain that usually begins at the tips of the toes or fingers and gradually spreads upward. Left untreated, you could lose all sense of feeling in the affected limbs. Damage to the nerves related to digestion can cause problems with nausea, vomiting, diarrhea or constipation. For men, it may lead to erectile dysfunction.
- Kidney damage (nephropathy). The kidneys contain millions of tiny blood vessel clusters (glomeruli) that filter waste from your blood. Diabetes can damage this delicate filtering system. Severe damage can lead to kidney failure or irreversible end-stage kidney disease, which may require dialysis or a kidney transplant. The rates of serious kidney disease have dropped significantly in recent years, likely due to improvements in diabetes management.
- Eye damage (retinopathy). Diabetes can damage the blood vessels of the retina (diabetic retinopathy), potentially leading to blindness. Diabetes also increases the risk of other serious vision conditions, such as cataracts and glaucoma.
- Foot damage. Nerve damage in the feet or poor blood flow to the feet increases the risk of various foot complications. Left untreated, cuts and blisters can become serious infections. Severe damage might require toe, foot or even leg amputation.
- Skin and mouth conditions. Diabetes may leave you more susceptible to skin problems, including bacterial and fungal
- Osteoporosis. Diabetes may lead to lower than normal bone mineral density, increasing your risk of osteoporosis.
- Alzheimer’s disease. Type 2 diabetes may increase the risk of Alzheimer’s disease. The poorer your blood sugar control, the greater the risk appears to be. One theory is that cardiovascular problems caused by diabetes could contribute to dementia by blocking blood flow to the brain or causing strokes. Other possibilities are that too much insulin in the blood leads to brain-damaging inflammation, or lack of insulin in the brain deprives brain cells of glucose.
- Cancer. People with diabetes have a higher risk of some cancers. But the reasons aren’t clear. It may be that the factors that increase the risk of type 2 diabetes also increase the risk of cancer, or it may be a factor of the disease or its treatment. This is an active area of research, but in the meantime, no changes in treatment are recommended.
Complications of gestational diabetes Most women who have gestational diabetes deliver healthy babies. However, untreated or uncontrolled blood sugar levels can cause problems for you and your baby.
Complications in your baby can occur as a result of gestational diabetes:
- Excess growth. Extra glucose can cross the placenta, which triggers your baby’s pancreas to make extra insulin. This can cause your baby to grow too large (macrosomia). Very large babies are more likely to require a C-section birth.
- Low blood sugar. Sometimes babies of mothers with gestational diabetes develop low blood sugar (hypoglycemia) shortly after birth because their own insulin production is high. Prompt feedings and sometimes an intravenous glucose solution can return the baby’s blood sugar level to normal.
- Respiratory distress syndrome. If your baby is delivered early, respiratory distress syndrome — a condition that makes breathing difficult — is possible. Babies who have respiratory distress syndrome may need help breathing until their lungs become stronger.
- Jaundice. This yellowish discoloration of the skin and the whites of the eyes may occur if a baby’s liver isn’t mature enough to break down a substance called bilirubin, which normally forms when the body recycles old or damaged red blood cells. Although jaundice usually isn’t a cause for concern, careful monitoring is important.
- Type 2 diabetes later in life. Babies of mothers who have gestational diabetes have a higher risk of developing obesity and type 2 diabetes later in life.
- Death. Untreated gestational diabetes can result in a baby’s death either before or shortly after birth.
Complications in you can also occur as a result of gestational diabetes:
- Preeclampsia. This condition is characterized by high blood pressure, excess protein in the urine, and swelling in the legs and feet. Preeclampsia can lead to serious or even life-threatening complications for both mother and baby.
- Subsequent gestational diabetes. Once you’ve had gestational diabetes in one pregnancy, you’re more likely to have it again with the next pregnancy. You’re also more likely to develop diabetes — typically type 2 diabetes — as you get older.
Complications of pre-diabetes Pre-diabetes may develop into type 2 diabetes.