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Diabetes: What Is It, Types, Risk Factors, Prevention

What is diabetes?

Diabetes mellitus is a long-term health condition that affects how a person’s body processes glucose or sugar. There are several types of diabetes, all can cause high blood sugar levels. Whether you have diabetes, are a caregiver or loved one of a person with diabetes, or just want to learn more, our resources will help you 

understand and navigate the most common types of diabetes.

Diabetes insipidus, on the other hand, is a rare condition where the body has trouble regulating the amount of water in the body. This happens when the body doesn't produce enough of a hormone called vasopressin, which helps the kidneys control the amount of water in the urine. As a result, people with diabetes insipidus often feel thirsty and need to urinate frequently, which can lead to dehydration if not managed properly.

Types of diabetes

Diabetes is a health condition in which most of the body’s cells can’t effectively convert sugar from food (called glucose) into energy. Insulin is the hormone that allows most cells to take up glucose from the bloodstream to use as energy or store for later. Diabetes occurs when the body doesn’t produce insulin and/or can’t use it efficiently, meaning that the body can’t maintain stable blood sugar levels.

  • Type 1 diabetes occurs when the body produces very little or no insulin. It makes up 5 to 10 percent of diabetes worldwide and often begins in childhood.

  • Type 2 diabetes occurs when the body can’t make enough insulin and cannot use available insulin efficiently. Most cases of diabetes are type 2 diabetes.

  • Gestational diabetes is diabetes during pregnancy in someone without type 2 diabetes. It happens when there is insufficient insulin and the available insulin cannot work efficiently due to changes within the mother’s body. It usually resolves after the baby is born.

Diabetes risk factors

Type 1 diabetes: If you have close family members with type 1 diabetes, then you are at a higher risk for the condition than the general population. 20% of people with the condition have a family member with T1D. Screening of family members of individuals with T1D has been proposed to detect new cases earlier.

Type 2 diabetes: You are at greater risk of type 2 diabetes if any of the following apply.

  • You have a family member who has type 2 diabetes

  • You have obesity or excess weight 

  • You have high blood pressure or high cholesterol 

  • You’re over the age of 40

  • You don’t do regular physical activity

  • Your parents or grandparents are Hispanic, Black, Native American, or Asian/ Pacific Islander

Gestational diabetes: You are at greater risk of gestational diabetes if any of the following apply.

  • You have prediabetes

  • You have a family history of diabetes

  • You have obesity or excess weight

  • You’re over the age of 25

  • You are of Hispanic, Black, Native American, Asian/Pacific Islander descent

  • You have previously given birth to an infant weighing more than 9 pounds

Diabetes prevention

Type 1 diabetes: There is currently no way to prevent type 1 diabetes. However, new treatment options, such as teplizumab, may delay the onset of type 1 diabetes. 80% of people with the condition do not have a family history of type 1 diabetes.

Type 2 diabetes: It is possible to lower your chances of type 2 diabetes. Type 2 diabetes develops through a combination of factors – elements of lifestyle, such as food, exercise, stress, and sleep play a role, as do family history and genetics. While type 2 diabetes is associated with obesity and weight loss is helpful, the condition is not simply the result of high body weight. To lower the risk of type 2 diabetes (and other diseases), exercise often, eat nutritious food, and maintain a healthy body weight

  • Exercise can reduce insulin resistance, lower body weight, increase muscle mass, and improve overall fitness. All adults should aim for 150 to 300 minutes each week of moderate-intensity aerobic activity (like walking), 75 to 150 minutes each week of vigorous aerobic exercise (like running), or some combination of the two types of exercise. Read expert exercise recommendations for people with diabetes here.

  • Healthy Nutrition can help people regulate blood sugar levels, and prevent the progression of type 2 diabetes or other health conditions. Focus on eating vegetables, lean proteins, and healthy fats, rather than carbohydrates that can spike blood sugar – learn more here.

Diabetes symptoms

Common symptoms of diabetes:

  • Urinating often

  • Feeling very thirsty

  • Feeling very hungry, even though you are eating

  • Extreme fatigue

  • Blurry vision

  • Cuts or bruises that are slow to heal

  • Weight loss, even though you may be eating more

Diabetes can develop slowly without any symptoms – particularly for type 2 diabetes – and many adults with diabetes may not know they have it for years. That’s why early screening for diabetes is important, especially if individuals have risk factors for type 2 diabetes. Type 1 diabetes symptoms appear more suddenly, and type 1 diabetes is often diagnosed in childhood.

Blood sugar swings associated with diabetes treated with medication may cause additional symptoms. Click to learn more about signs of low blood sugar (hypoglycemia) and what to do about it.

Diagnosing diabetes

To determine if you have diabetes, talk with a healthcare professional. To diagnose type 1 or type 2 diabetes, your healthcare professional will likely recommend one or more of these tests:

  1. An A1C test (also called a glycated hemoglobin test, or HbA1c). This blood test gives an estimate of a person’s average blood sugar levels from the past two or three months. An A1C of 6.5% or higher is considered diabetes (5.7% to 6.4% is considered prediabetes, and an A1C below 5.7% is considered normal).

  2. A fasting plasma glucose (FPG) test measures a person’s blood glucose level after a period of fasting (not eating) for eight hours. An FPG of 126 mg/dl or higher indicates diabetes. (100 to 125 mg/dL is prediabetes and below 100 is normal)

  3. In someone with or without symptoms of high blood sugar (or hyperglycemia), a random plasma glucose test can be used to check blood sugar levels. A blood sugar level above 200 mg/dl indicates diabetes.

Healthcare professionals may also suggest diabetes-related antibody tests to specifically confirm a diagnosis of type 1 diabetes.

Diabetes-related health challenges

Diabetes increases a person’s risk of developing medical complications. Over time, the high blood sugar levels that characterize diabetes can damage the body, affecting the nervous system, blood vessels, eyes, heart, and kidneys. These complications impact quality of life and increase a person’s risk for events like a heart attack or stroke, but careful blood glucose management decreases the chance that these complications will occur.

Learn more about diabetes-related health challenges:

Managing diabetes

Currently, there is no cure for either type 1 or type 2 diabetes. However, careful diabetes management can help people with diabetes (PWD)  feel better and prevent further health challenges. For everyone with diabetes, healthy eating, exercise, and weight management are key to managing the condition.

Note: Early in the course of type 2 diabetes, it is possible to manage diabetes to a level where symptoms go away and A1Cs reach normal levels – this effectively “reverses” the progression of type 2 diabetes, putting diabetes into remission. However, diabetes remission is not the same as curing type 2 diabetes, and you must carefully maintain healthy habits to keep diabetes from returning. 

Diabetes drugs 

People with diabetes often take medication to help stabilize their blood sugar levels. People with type 1 diabetes usually must take insulin daily, while people with type 2 diabetes may use other medications. People with type 2 diabetes will commonly use a combination of medications to help manage their diabetes.

These are the most common diabetes drugs used to lower blood sugar levels:


What it Treats

How it Works to Lower Glucose


Type 1 diabetes, type 2 diabetes

Helps most cells take up glucose to use for energy.


Type 2 diabetes

Decreases glucose production from the liver.

SGLT-2 inhibitors

Type 2 diabetes

Blocks the kidneys from reabsorbing glucose.

GLP-1 receptor agonists 

Type 2 diabetes

Stimulates insulin release and inhibits glucagon release. Also reduces appetite.

DPP-4 inhibitors

Type 2 diabetes

Inhibits enzyme DPP-4 to increase hormone GLP-1,which stimulates insulin production and inhibits glucagon release.

Combination drugs

Type 2 diabetes

Includes multiple diabetes drugs in a single medication.


Type 2 diabetes

Stimulates cells in the pancreas to release insulin.


Type 2 diabetes

Reduces insulin resistance in fat cells. 

Types of insulin

There are two main types of insulin: long-acting or basal insulin and rapid-acting or prandial (meal-time) insulin. 

  • Long-acting insulin is taken once or twice per day to provide a constant, low level of insulin action.While it helps keep blood sugars at a consistent level when someone is  not eating, it can’t cover glucose spikes after a meal. 

  • Rapid-acting insulin is taken before meals and acts rapidly in the body, stabilizing blood sugar levels after eating.

  • Insulin devices like insulin pumps or pods only use rapid-acting insulin.

People who use insulin may also need to take glucagon if blood glucose levels drop too low. Glucagon is a drug that can quickly raise blood glucose levels. (Learn more about glucagon and hypoglycemia here).

Diabetes devices 

People with diabetes use technology to help monitor blood sugar levels. These are the most commonly used categories of diabetes devices:

  • Blood glucose meters are portable devices designed to measure your blood glucose level at a specific moment in time. 

  • Continuous glucose monitors (CGM) measure glucose levels continuously, in real-time, through a sensor attached to your skin.

  • Injection pens are used to inject a precise amount of a diabetes drug, without the need for a syringe.

  • Insulin pumps and pods are worn on the body to deliver insulin without the need for injections.

  • Automated insulin delivery (AID) systems combine continuous glucose monitors, insulin pumps, and smart algorithms to measure glucose levels and adjust insulin delivery via the pump to keep blood sugar levels as stable as possible throughout the day and night.

  • Mobile coaching services help people with diabetes connect to healthcare professionals online. The goal of mobile coaching is to advise people on their health and improve diabetes management through access to 24/7 remote care.

More diabetes resources

Time in Range (TIR): The percentage of time a person spends with their blood glucose levels in a safe target range – usually between 70 mg/dl and 180 mg/dl.

Diet and nutritionNutrition is important for everyone, with or without diabetes. But for people with diabetes, what you eat greatly affects your blood sugar levels, Time in Range, long-term health outcomes, and your potential for weight gain. Healthy eating habits can help lead to positive short- and long-term health outcomes.

ExercisePhysical activity, even walking after meals, can help reduce blood sugar levels. Read expert exercise recommendations for people with type 1 or type 2 diabetes here.

Access to care: Accessing medication and treatment may be a challenge for people with diabetes. Find resources on affording care and navigating health insurance. 

Weight lossLosing weight and building muscle reduces insulin resistance, which is one of the underlying factors that cause type 2 diabetes. That’s why weight management – through diet and exercise – is especially important for managing type 2 diabetes.