What Is Diabetes?

Reviewed on 8/15/2022

What is Diabetes?

Diabetes Treatment
Diabetes Treatment

Diabetes is a disease in which the body cannot produce enough insulin or is unable to use insulin as it should, resulting in high blood sugar (glucose) levels. When we eat, the body converts foods into glucose to use as energy. An organ called the pancreas makes the hormone insulin, which helps the body use glucose for energy. In diabetics, this process does not work properly, causing a buildup of glucose in the blood.

  • The two main types of diabetes are type 1 diabetes and type 2 diabetes. There is also gestational diabetes which develops during pregnancy, and some other less common forms of diabetes.
  • More than 29 million people in the U.S. have diabetes, and it is the leading cause of medical conditions such as kidney failure, blindness, amputations, heart failure, and stroke.

What is Type 2 Diabetes?

Type 2 diabetes is the most common form of diabetes. Also called non-insulin-dependent diabetes mellitus, or "adult-onset" diabetes, this type usually develops in adults over age 35 and is more common in people who are overweight or obese, and who are not physically active.

In type 2 diabetes, the body can produce some insulin, but usually not enough to let the glucose into the cells to use as energy for the body. There is also insulin resistance, where the body has difficulty using the insulin it does produce.


Diabetes is defined best as... See Answer

What Are Type 1 and Type 2 Diabetes? Causes

Type 1 diabetes is less common but more severe than type 2 diabetes. Only about 5% of people have this form, also called insulin-dependent diabetes mellitus, and formerly referred to as "juvenile" diabetes, because it usually develops in children and teenagers, though adults can also be diagnosed.

Type 1 diabetes is an autoimmune disorder. The body's immune system attacks and destroys the insulin-producing cells (beta cells) in the pancreas and so the body does not produce insulin. The cells don't get the glucose they need, causing a buildup of glucose in the blood (high blood sugar) that can lead to diabetic ketoacidosis, a condition in which the glucose level is very high and acid builds up in the body.

What Causes Diabetes?

The causes of diabetes differ depending on the type of diabetes.

  • Causes of type 1 diabetes
    • Type 1 diabetes is an autoimmune disorder, caused by the body's immune system attacking and destroying the cells in the pancreas that produce insulin (beta cells).
    • Genetics are a major cause of developing type 1 diabetes. A type of gene variant called a human leukocyte antigen (HLA) is the major gene linked to a higher risk for developing type 1 diabetes.
    • Environmental factors, such as foods, viruses, and toxins, may affect whether a person with a genetic susceptibility develops type 1 diabetes, but this is not completely understood.
  • Causes of type 2 diabetes
    • There are a number of factors that influence the development of type 2 diabetes, including insulin resistance, genetics, obesity, sedentary lifestyle, abnormal glucose production by the liver, metabolic syndrome, problems with cell signaling, and beta cell dysfunction.
    • Insulin resistance is a condition in which muscle, fat, and liver cells stop responding to the hormone insulin. The pancreas is still producing insulin but it is not being effectively used by the body, leading to a buildup of glucose (sugar) in the blood, which leads to prediabetes or diabetes. Insulin resistance is common in people who are overweight or obese, or not physically active.
    • Obesity and lack of physical activity can cause type 2 diabetes, especially in people with genetic risk. Excess abdominal fat in particular is a major risk factor.
    • Abnormal glucose production by the liver can also lead to high blood glucose levels.
    • A metabolic syndrome is a group of conditions that includes higher than normal blood glucose levels, excess abdominal fat and increased waist size, high blood pressure, and high cholesterol and triglycerides.
    • Cell signaling – the way cells communicate with each other to regulate body processes – may not work properly in people with diabetes.
    • Insulin-producing beta cells in the pancreas may be damaged and this dysfunction can cause insufficient or abnormal insulin release.

What are the types of diabetes?

  • The two main types of diabetes are type 1 diabetes (formerly called juvenile diabetes) and type 2 diabetes (formerly called adult-onset diabetes).
  • Gestational diabetes develops during pregnancy, typically around the 24th week. The causes of gestational diabetes are not completely understood but the hormones from the placenta that help the baby develop are believed to block the insulin in the mother's body leading to insulin resistance (difficulty or inability to use insulin).
  • Latent autoimmune diabetes of adulthood (LADA) is a new term for patients whose diabetes more closely resembles type 1 diabetes, but don't quite have all the symptoms. Often misdiagnosed as type 2 diabetes, LADA – also sometimes called type 1.5 diabetes – is believed to be a slowly progressing version of type 1 diabetes.
  • Double diabetes is the term used when a person with type 1 diabetes develops insulin resistance, which is a symptom of type 2 diabetes.
  • Monogenic diabetes, caused by defects in a single gene, is rare and includes neonatal diabetes mellitus (NDM) which occurs in the first 6 months of life, and maturity-onset diabetes of the young (MODY) which usually develops during adolescence or early adulthood.
  • Secondary diabetes is the name for diabetes that results from other medical conditions, such as cystic fibrosis, chronic pancreatitis, pancreatic cancer, Cushing's syndrome, polycystic ovarian syndrome (PCOS), and hemochromatosis.
  • Diabetes insipidus is a rare condition caused by kidney dysfunction, that results in excessive thirst and passing large amounts of dilute urine. It is unrelated to diabetes mellitus (both types 1 and 2).
  • Alzheimer's disease is sometimes called type 3 diabetes because it's a result of insulin resistance in the brain.

What are symptoms and signs of diabetes?

Symptoms of type 1 diabetes and type 2 diabetes are similar in men, women, and in children. Type 2 diabetes may have no symptoms.

Common symptoms and signs of diabetes include:

  • Frequent urination
  • Extreme thirst or hunger
  • Extreme fatigue
  • Blurred vision
  • Slow wound healing

Symptoms of type 1 diabetes may also include:

  • Nausea, vomiting, abdominal pain
  • Weight loss (even if you are eating more)
  • Mood changes
  • Fast heart rate
  • Headache
  • Sleepiness
  • Sweating
  • Changes in menstruation
  • Blood pressure drops below 90/60
  • Low body temperature (below 97F)

Symptoms of type 2 diabetes may also include:

  • Tingling, pain, or numbness in the extremities
  • Weight changes (gain or loss)
  • Recurrent yeast infections

In women with gestational diabetes, there may be no signs or symptoms. Women should be monitored by their doctors during pregnancy.

What is Diabetic Neuropathy?

Diabetic neuropathy is a type of nerve damage caused by diabetes that affects about half of people with diabetes. Chronic exposure to high blood glucose damages the nerves. Nerve damage is more common in people who have difficulty controlling their blood sugar, are overweight or obese, have kidney disease, have high blood pressure, or who smoke.

Symptoms of diabetic neuropathy include:

  • Numbness, pain, or tingling in the hands, fingers, feet, toes, arms, and legs
  • Muscle wasting in the feet or hands
  • Weakness
  • Nausea or vomiting
  • Diarrhea or constipation
  • Dizziness upon standing
  • Difficulty urinating
  • Erectile dysfunction in men
  • Vaginal dryness in women


Diabetes: What Raises and Lowers Your Blood Sugar Level? See Slideshow

What is diabetes treatment?

Treatment for type 1 diabetes requires insulin in addition to lifestyle changes. Insulin may be taken in several injections each day, or with the use of an insulin pump.

People with diabetes often need to take insulin, because they do not produce insulin or their bodies do not use the insulin they produce properly. Different types of insulin vary in how they are made, how quickly they work when they peak, how long they last, and how much they cost. The most common strength in the U.S. is U-100, which means it has 100 units of insulin per milliliter of fluid.

Types of insulin include:

  • Rapid-acting insulin: Taken before a meal, works in about 15 minutes, lasts 2-4 hours, and Helps cover the rise in blood glucose from eating. Usually used along with longer-acting insulin. Examples: insulin glulisine (Apidra), insulin lispro (Humalog), insulin aspart (NovoLog)
  • Short-acting insulin (or regular insulin): Taken before a meal, works in about 30 minutes, peaks around 2 to 3 hours, effective for 3 to 6 hours. Usually used along with longer-acting insulin. Examples: Humulin R, Novolin R
  • Intermediate-acting insulin: Reaches the bloodstream about 2 to 4 hours after injection, peaks 4 to 12 hours afterward, effective for 12 to 18 hours. Normally taken twice daily, intermediate-acting insulin is usually taken in combination with rapid-acting insulin or short-acting insulin. Examples: NPH (Humulin N, Novolin N)
  • Long-acting insulin: Usually taken once or twice daily, reaches the bloodstream in several hours, and evenly lowers blood glucose levels over 24 hours. Often combined with rapid-acting insulin or short-acting insulin. Examples: insulin detemir (Levemir), insulin glargine (Lantus)

Some patients have insulin delivered through an insulin pump, a small computerized device that can deliver insulin to the body either as a programmed measured and continuous dose ("basal" insulin) or as a surge dose ("bolus") taken when needed, usually around meals. The dose of insulin is delivered through a catheter that is inserted through the skin into fatty tissue and taped in place. Many patients prefer insulin pumps over injections because they can achieve better blood sugar control.

In addition to insulin, lifestyle changes to treat type 1 diabetes include:

  • Monitor blood sugar levels
  • Eat a healthy diet
  • Regular exercise
  • Avoid alcohol
  • Do not smoke
  • Have regular medical checkups

Treatment for type 2 diabetes starts with a healthy diet, meal planning, weight loss, and exercise, and some people may not need medications. Others may be prescribed oral diabetes medications and/or insulin to maintain healthy blood glucose levels.

There are numerous classes of anti-diabetic drugs that work in different ways to lower blood sugar (glucose) levels. Often different drugs will be used in combination.

Many people try herbal supplements in hopes of managing their diabetes. The American Diabetes Association states research has not shown dietary supplements to be effective in managing blood sugar levels in diabetic patients. Supplements commonly touted to do so include omega-3 fatty acids, cinnamon, vinegar, vitamin B1, alpha-lipoic acid (ALA), bitter melon, green tea, and magnesium. Before taking any herb or dietary supplement, talk to your doctor because many can interact with medications and cause side effects.

Diabetes Diet

Diet and exercise are extremely important in managing diabetes and also insulin resistance. Staples of a nutritious diet that can help manage blood sugar levels include fruits, vegetables, whole grains, legumes, lean meats, and low-fat dairy. Meal planning is essential.

Check out the American Diabetes Association for recipes. (http://www.diabetes.org/mfa-recipes/recipes/?loc=ff-slabnav)

Understand the Blood Sugar Chart

The Blood Sugar Chart
Times to Check Blood Glucose Plasma blood glucose
goal ranges
(for people with diabetes)
Fasting, Before breakfast 70 - 130
Before meals and snacks 70 - 130
Two hours after meals <180
Bedtime 90-150
American Diabetes Association. Symptoms - See more at: http://www.diabetes.org/diabetes-basics/symptoms/#sthash.IfBiMeJE.dpuf. 2016. 9 May 2016 .
American Diabetes Association. Medication. 2016. 9 May 2016 .
Diabetes Research Institute Foundation. What is Diabetes? . 2016. 9 May 2016 .
Diabetologia. Insulin resistance in type 1 diabetes: what is ‘double diabetes' and what are the risks? July 2013. 9 May 2016 .
Journal of Diabetes Science and Technology. Alzheimer's Disease Is Type 3 Diabetes–Evidence Reviewed. November 2008. 9 May 2016 .
The National Institute of Diabetes and Digestive and Kidney Diseases. Diabetes Insipidus. October 2015. 9 May 2016 .
The National Institute of Diabetes and Digestive and Kidney Diseases. Diabetic Neuropathies: The Nerve Damage of Diabetes. November 2013. 9 May 2016 .
The National Institute of Diabetes and Digestive and Kidney Diseases. Diagnosis of Diabetes and Prediabetes . June 2014. 9 May 2016 .
The National Institute of Diabetes and Digestive and Kidney Diseases. Causes of Diabetes. June 2014. 9 May 2016 .

Health Solutions From Our Sponsors