What is diabetes?

Diabetes mellitus, the condition commonly referred to as diabetes, is a disease that affects how your body makes and handles the hormone insulin. This hormone directly affects your blood sugar (glucose) levels by allowing sugar to enter cells. Cells then use sugar for energy. Diabetes results when your body either can’t make enough insulin or becomes resistant to the insulin it makes.
There are several ways that diabetes develops. One way this happens is when insulin-producing cells in the pancreas are damaged, causing no or low insulin. Without insulin, sugar remains in the blood rather than going into cells that need energy. The result is a low blood level of insulin and a high blood sugar level.
The second way that diabetes happens is when the pancreas makes insulin, but body cells become resistant to its effect. If cells do not respond to insulin, they will not let sugar enter. In this case, blood insulin levels are high, and blood sugar levels remain high. In both cases, other health problems result when sugar levels in the blood remain high over time.
Over 37.3 million American adults have diabetes. The most common types of diabetes are diabetes type 1 and type 2. However, there are several other types of diabetes identified, as well as new categories suggested from current research.
What are the major types of diabetes?
According to the Centers for Disease Control and Prevention (CDC), the three main types of diabetes are diabetes type 1, type 2, and gestational diabetes. The CDC also mentions prediabetes as a type.
Diabetes type 1
Type 1 occurs when your immune system attacks insulin-producing beta cells in your pancreas, an autoimmune disease. Type 1 diabetes results in damaged pancreas cells that can’t produce insulin. Without insulin, high blood sugar levels result.
About 5% to 10% of people with diabetes have type 1. With this type, symptoms of diabetes develop quickly and most often in children or young adults. However, it can occur at any age.
Symptoms include the following:
- Frequent urination
- Feeling thirsty
- Losing weight rapidly
- Feeling hungry
- Having blurry vision
- Numbness or tingling in hands or feet
- Feeling extremely tired
- Having dry skin and sores that heal slowly
- Having more infections than usual
Diabetes type 1 can be controlled by continuously monitoring blood sugar levels and taking insulin as needed. There are no known ways to prevent type 1 diabetes.
Diabetes type 2
Diabetes type 2 is the most common form. Approximately 90% to 95% of people with diabetes have type 2. With diabetes type 2, your body can’t use insulin properly, which increases blood sugar levels.
While most commonly found in adults, children can also be diagnosed with type 2 diabetes. It can take years to develop and may not show symptoms. Its symptoms are similar to but milder than diabetes type 1. However, if left untreated, diabetes type 2 can cause complications that affect the eyes, heart, and feet.
Testing blood sugar levels are necessary for diagnosis. For diabetes treatment, you’ll need to regularly monitor your blood sugar levels and take insulin or diabetes medication to control them. Lifestyle changes can prevent type 2 diabetes, including weight loss, healthy eating, and exercise.
Gestational diabetes develops during pregnancy. It occurs in women who have never had diabetes. With gestational diabetes, you and your baby can be at a higher risk of health problems.
Gestational diabetes may not show any symptoms. A blood test at 24 to 28 weeks of pregnancy diagnoses gestational diabetes. It usually goes away after your baby is born. But it can increase your risk of developing diabetes type 2 later in life. It can also increase the risk of your baby experiencing obesity or diabetes type 2 later in life.
In America, about 96 million adults have prediabetes. If you have prediabetes, your blood sugar levels are higher than normal, but not high enough to be diagnosed as diabetes type 2. Prediabetes increases your risk of developing diabetes type 2, heart problems, and stroke. You can reverse the condition by regularly monitoring your blood sugar levels and changing your lifestyle.
Other types of diabetes
Apart from the main types, there are other types of diabetes caused by genetic mutations, health conditions, or other factors.
They are as follows:
Latent autoimmune diabetes in adults (LADA)
This type of diabetes has features of diabetes type 1 and type 2. It is often called diabetes type 1.5. Studies are currently underway to understand how it is different from diabetes type 1 and 2.
Diabetes type 3
The term diabetes type 3 was first proposed in a 2005 research review, to explain how insulin resistance can lead to Alzheimer’s disease, a type of dementia.
Another research review in 2018 showed that people with diabetes type 2 have a higher risk of developing Alzheimer’s disease. Type 3 is not officially an accepted diabetes type. However, it is currently under research.
Diabetes type 4
Diabetes type 4 describes diabetes caused by age-related insulin resistance in people who are not overweight or obese. Type 4 is not an officially recognized category. Studies only looked at animals, like mice, and have not included humans.
Maturity onset diabetes of the young (MODY)
MODY is different from diabetes type 1 and 2. It is a rare, genetic type of diabetes. Up to 2% of all people with diabetes in America who are 20 or younger may develop this condition.
Caused by a change or mutation in a single gene, it is a monogenic condition. This mutation affects insulin production, resulting in high blood sugar levels. If one of your parents has this mutation, you have a 50% chance of getting it. Those who inherit this gene mutation develop MODY before they turn 25, regardless of their lifestyle.
Neonatal diabetes
Neonatal diabetes is another type of monogenic diabetes, occurring due to a mutation in a single gene. Typically, diagnosis occurs between 6 and 12 months of age. A rare condition, it affects 1 out of 400,000 American infants.
Neonatal diabetes is often confused with diabetes type 1. Its symptoms include frequent urination, rapid breathing, and dehydration. Diagnosis is by testing sugar levels in the blood or urine.
Diabetes type 3c
Type 3c diabetes happens when the pancreas is damaged or removed. Other diseases affecting the pancreas like pancreatic cancer, pancreatitis, or hemochromatosis can damage the insulin-producing cells, resulting in diabetes type 3c.
Wolfram syndrome
Wolfram syndrome is a rare genetic disorder that includes four presenting features: diabetes insipidus (a condition unrelated to blood sugar but characterized by increased urine output), diabetes mellitus, optic atrophy, and deafness.
Alström syndrome
Alström Syndrome is a rare, genetically inherited syndrome, characterized by common findings. One finding is insulin resistance in childhood, leading to type 2 diabetes.
Steroid-induced diabetes
Steroids can cause diabetes in people who are otherwise at risk of developing diabetes type 2.
Cystic fibrosis-related diabetes
This type of diabetes occurs in people with cystic fibrosis. It has features similar to diabetes types 1 and 2.Check your blood sugar levels
If you suspect diabetes, get your blood sugar levels checked. Your doctor may also check your family history of diabetes. They may prescribe insulin or diabetic medication and suggest lifestyle changes to reverse the condition.

SLIDESHOW
Diabetes: What Raises and Lowers Your Blood Sugar Level? See SlideshowCenter for Disease Control and Prevention: "Diabetes Symptoms," "Insulin Resistance and Diabetes," "What is Diabetes?"
Diabetes UK: "Monogenic Diabetes (Neonatal Diabetes Mellitus & MODY)," "Types of Diabetes."
Frontiers in Neuroscience: "Insulin Resistance in Alzheimer's Disease."
Journal of Alzheimer's Disease: "Impaired insulin and insulin-like growth factor expression and signaling mechanisms in Alzheimer's disease--is this type 3 diabetes?"
National Institutes of Health: “What is Diabetes?"
Nature: "Depletion of Fat Tregs Prevents Age-Associated Insulin Resistance."
Salk: "FAQ on Type 4 Diabetes.”
Top How Many Types of Diabetes Are There Related Articles
Diabetes Foot Problems
Learn more about diabetes related foot problems. For people with diabetes, too much glucose in the blood can cause serious foot complications such as nerve damage, infection, and ulcers. Find tips for proper foot care to help prevent serious complications.Diabetes (Type 1 and Type 2)
Diabetes is a chronic condition characterized by high levels of sugar (glucose) in the blood. The two types of diabetes are referred to as type 1 (insulin dependent) and type 2 (non-insulin dependent). Symptoms of diabetes include increased urine output, thirst, hunger, and fatigue. Treatment of diabetes depends on the type.Diabetes Quiz
Take the Diabetes Quiz and learn the causes, signs, symptoms, and types of this growing epidemic. What does diabetes have to do with obesity and diet? Learn about life as a diabetic.Diabetes Treatment: Medication, Diet, and Insulin
The major goal in treating diabetes is controlling elevated blood sugar without causing abnormally low levels of blood sugar. Type 1 diabetes is treated with:
- insulin,
- exercise,
- and a diabetic diet.
Type 2 diabetes is first treated with:
- weight reduction,
- a diabetic diet,
- and exercise.
When these measures fail to control the elevated blood sugar, oral medications are used. If oral medications are still insufficient, insulin medications are considered.
Type 2 Diabetes Diet Plan
A type 2 diabetes diet or a type 2 diabetic diet is important for blood sugar (glucose) control in people with diabetes to prevent complications of diabetes. There are a variety of type 2 diabetes diet eating plans such as the Mediterranean diet, Paleo diet, ADA Diabetes Diet, and vegetarian diets.Learn about low and high glycemic index foods, what foods to eat, and what foods to avoid if you have type 2 diabetes.Exercises for Diabetes Nerve Pain
Learn how to cope with the symptoms of diabetic peripheral neuropathy through pain management exercises. Find relief for diabetic nerve pain without medication.Insulin Pump for Diabetes
An insulin pump is designed to deliver insulin directly to a patient with diabetes. They are about the size of a standard beeper. The pump is attached to under the skin (usually on the abdomen). The amount of insulin required will depend on lifestyle (exercise, sleep patterns, activity level, and diet).Prediabetes
Prediabetes is a situation where a person's blood sugar levels are higher than they should be, but aren't high enough to be diagnosed with type 2 diabetes. There are no signs or symptoms of prediabetes. Some of the risk factors for prediabetes are
- high blood pressure,
- high cholesterol,
- heart disease,
- smoking,
- family history,
- poor diet, and
- lack of activity.
Diet changes along with other healthy lifestyle changes are important in treating prediabetes.
Type 1 Diabetes (Symptoms, Causes, Diet, Treatment, Life Expectancy)
Type 1 diabetes mellitus (juvenile) is an auto-immune disease with no known cause at this time, although there are a few risk factors. Symptoms of type 1 diabetes include frequent urination, unintentional weight loss, dry and itchy skin, vision problems, wounds that heal slowly, and excessive thirst. Type 1 diabetes is diagnosed with blood tests. A healthy lifestyle and controlling blood glucose levels can improve life expectancy.Type 1 Diabetes
What is type 1 diabetes? There are new treatments for juvenile diabetes, and more people with diabetes can be treated than ever before. Learn the symptoms of T1D, the causes, and find ways to control your blood glucose levels naturally.Type 1 Diabetes Quiz
What are the causes of type 1 diabetes? Take this quiz and challenge your knowledge of causes, symptoms, diagnosis and treatments for this common condition, formerly known as juvenile diabetes.Type 1 vs. Type 2 Diabetes: Differences
Diabetes mellitus is a metabolic condition in which a person's blood sugar (glucose) levels are too high. Over 29.1 million children and adults in the US have diabetes. Of that, 8.1 million people have diabetes and don't even know it. Type 1 diabetes (insulin-dependent, juvenile) is caused by a problem with insulin production by the pancreas. Type 2 diabetes (non-insulin dependent) is caused by:
Eating a lot of foods and drinking beverages with simple carbohydrates (pizza, white breads, pastas, cereals, pastries, etc.) and simple sugars (donuts, candy, etc.)
- Consuming too many products with artificial sweeteners (We found out that they are bad for us!)
- Lack of activity
- Exercise
- Stress
- Genetics
While the signs and symptoms of both types of diabetes are the same, which include:
- Increased urination
- Increased hunger
- Increased thirst
- Unexplained weight loss.
However, the treatments are different. Type 1 diabetes is insulin dependent, which means a person with this type of diabetes requires treatment with insulin. People with type 2 diabetes require medication, lifestyle changes like eating a healthy diet, and getting regular exercise.
Type 2 Diabetes
Type 2 diabetes is a chronic condition that may be reversible with diet and lifestyle changes. Symptoms include excessive thirst, frequent urination, weight loss, fatigue, and an unusual odor to your urine. Most people don't know they have type 2 diabetes until they have a routine blood test. Treatment options include medications, a type 2 diabetes diet, and other lifestyle changes.Type 2 Diabetes Quiz
What causes type 2 diabetes? Can it be prevented? Take this online quiz and challenge your knowledge of this common condition. Also, get the truth about myths and facts!Type 2 Diabetes Signs
Learn about type 2 diabetes warning signs, symptoms, diagnosis, and treatment options. Find out why thirst, headaches, and infections could be signs of diabetes. Discover the treatment options for people with type 2 diabetes, including medicines and lifestyle improvements.Diabetes Urine Tests
Urine tests for individuals with diabetes is important to check for diabetes-related kidney disease and severe hypoglycemia. With proper monitoring of blood glucose levels, diabetic-kidney disease can be avoided.Which is Worse - Type 1 or Type 2 Diabetes?
Learn about the similarities and differences between Type 1 and Type 2 Diabetes.