When you look at the numbers, the rate of diabetes in the U.S. is alarming. One in eight adults in the United States has diabetes, according to 2026 estimates from the Centers for Disease Control and Prevention. On top of that, an estimated 42% of adults have prediabetes, a condition that frequently progresses to diabetes if unmanaged.
What makes the growing prevalence of diabetes so concerning is that living with diabetes puts people at higher risk for other serious health problems. Diabetic retinopathy, for instance, is the leading cause of blindness in working-age adults and can lead to end-stage renal disease. Furthermore, if you have diabetes, you’re twice as likely to have heart disease or a stroke than someone who doesn’t have the disease.
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Types of Diabetes
There are several different types of diabetes. The most common are Type 1 and Type 2 diabetes.
Type 1 diabetes
Type 1 diabetes is an autoimmune disease in which the body’s immune system mistakenly attacks and destroys insulin-producing cells, known as beta cells, in the pancreas. Once these cells have been attacked, the body is unable to manufacture enough insulin on its own. Insulin is responsible for:
— Converting energy by turning sugar from carbohydrates into usable fuel
— Storing glucose for your body to use for future activities
— Regulating blood sugar levels so they don’t spike or drop too low
Formerly known as juvenile diabetes and insulin-dependent diabetes, Type 1 diabetes requires lifelong management.
Type 2 diabetes
While Type 1 diabetes is characterized by a complete lack of insulin, Type 2 diabetes develops when the body becomes resistant to the insulin it does produce. This is far and away the most common type of diabetes. About 95% of people with the disease have Type 2 diabetes, also known as noninsulin-dependent diabetes, the CDC reports.
Prediabetes
Almost half of the U.S. adult population, about 115 million adults, have prediabetes, the CDC notes. If left untreated, prediabetes can lead to Type 2 diabetes.
But prediabetes is not just a warning sign for diabetes; it is its own independent health condition. The insulin resistance that occurs in prediabetes can also lead to cancer, coronary artery disease, dementia and many of the other health conditions that diabetes can cause.
Gestational diabetes and other secondary types
While Type 1 and Type 2 account for nearly all diabetes cases, gestational diabetes and other secondary types of diabetes also occur.
— Gestational diabetes: This type develops during pregnancy in people who do not already have diabetes, affecting between 5% and 9% of pregnancies in the U.S. annually, according to the CDC. Gestational diabetes can raise the risk for a number of health issues, including high blood pressure during pregnancy and having a large baby, which can increase the chance of injuries during delivery to the mother or child. A cesarean section is sometimes needed in these situations.
— Type 3 diabetes: Some researchers have theorized that there is a Type 3 diabetes that causes Alzheimer’s disease. These researchers believe Alzheimer’s disease is caused by a kind of insulin resistance and insulin dysregulation in the brain. However, most health associations and many clinicians do not recognize Type 3 diabetes as an official diagnosis.
— Type 3c diabetes: Type 3c diabetes, often misdiagnosed as Type 2 diabetes, is a little-known form of diabetes also known as pancreatogenic diabetes. This form of diabetes occurs when the pancreas stops producing enough insulin, which can happen with illnesses such as pancreatic cancer, pancreatitis or hemochromatosis. Type 3c diabetes is estimated to affect 5% to 10% of all people with diabetes, according to research published in the Journal of the American Academy of Physician Assistants in 2022.
— Maturity onset diabetes for the young: This rare and inherited form of diabetes is caused by a gene mutation that disrupts insulin production.
— Latent autoimmune diabetes in adults: This form, often called Type 1.5, is a slow-progressing autoimmune condition frequently misdiagnosed as Type 2 diabetes.
Causes and Risk Factors
Depending on the type, diabetes can have multiple causes and risk factors.
Type 1 diabetes risk factors
The exact cause of Type 1 diabetes is unknown. However, the following factors may contribute to risk:
— Family history: Individuals with a parent or sibling with Type 1 diabetes have a slightly increased risk of developing the condition.
— Previous viral illness: A viral illness can trigger the immune system, which can lead to the development of Type 1 diabetes.
— Age: While Type 1 diabetes can appear at any age, it occurs at two noticeable peaks: The first peak occurs in children between ages 4 and 7, and the second peak is in kids between ages 10 and 14.
“While most people are diagnosed with Type 1 diabetes in their teens and 20s, people can develop Type 1 diabetes at any time. I once diagnosed a person in her 70s,” says Dr. Gillian Goddard, a New York City-based board-certified endocrinologist, nutritionist and adjunct assistant professor of medicine at the NYU Grossman School of Medicine.
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Risk factors for Type 2, prediabetes and gestational diabetes
Because Type 2 diabetes, prediabetes and gestational diabetes share insulin resistance-related root causes, their risk factors overlap:
— Genetics and family history: If one parent has Type 2 diabetes, for instance, your chance of developing Type 2 diabetes is between 35% and 40%, Goddard says. If both parents have it, that probability surges to 60% or more.
— Lifestyle factors: Eating an unhealthy diet, combined with inactivity and having excessive fat, particularly around the abdomen, can contribute to your risk of developing prediabetes, gestational diabetes and Type 2 diabetes.
— Ethnicity: Individuals who identify as Black, Hispanic or American Indian have a higher risk of developing Type 2 diabetes.
— Gestational-specific age risk: Women over 25 are also more likely to develop gestational diabetes.
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Symptoms and Early Warning Signs
Learning to recognize the early warning signs of diabetes can help you map out any preventive measures and potential treatment options.
Common symptoms of diabetes (all types)
— Increased thirst
— Frequent urination
— Bed-wetting in children who previously didn’t wet the bed at night
— Extreme hunger
— Unintended weight loss
— Irritability and other mood changes
— Fatigue and weakness
— Blurred vision
— Slow-healing sores
— Frequent infections
— Areas of darkened skin, typically around the armpits and neck
— Increased yeast infections
— Increased urinary tract infections
— Numbness or tingling in the hands and feet
Diabetic ketoacidosis symptoms
In addition to the symptoms above, people with diabetes with very high sugar levels may develop a condition called diabetic ketoacidosis, which has symptoms like:
— Nausea
— Vomiting
— Fruity odor to breath
— In severe cases, rapid breathing, known as Kussmaul respirations, which requires prompt emergency evaluation
Type 1 diabetes progression
Early symptoms of Type 1 diabetes are often easy to miss, says Dr. Bethany Gottesman, an endocrinologist at Phoenix Children’s Hospital in the greater Phoenix area.
“If you are diagnosed with Type 1 diabetes, there was nothing you did or did not do that caused the diabetes or could have prevented it,” she points out.
Type 1 diabetes has no cure and requires lifelong management. With modern technology, life expectancy for individuals with diabetes is now close to normal ranges.
Type 2 diabetes and prediabetes progression
Prediabetes and Type 2 diabetes typically progress slowly and develop over time, Gottesman says.
“After years of making increased amounts of insulin, eventually the pancreas can no longer produce enough to keep blood sugars in the normal range. So even though the body may still be making a lot of insulin, it is not enough to meet that person’s needs,” Gottesman explains.
Gestational diabetes progression
Many women may not have noticeable signs or symptoms of gestational diabetes because of their overlap with pregnancy-related issues, such as increased urination and fatigue.
Typically, gestational diabetes resolves after childbirth, but it does increase the likelihood of developing Type 2 diabetes later in life.
Diagnosis and Diagnostic Testing
Your primary healthcare provider can diagnose diabetes with an array of blood tests.
| Test Type | Normal Range | Prediabetes Threshold | Diabetes Threshold | Details |
| A1c test | Below 5.7% | 5.7% to 6.4% | 6.5% or higher | The A1c test measures your blood sugar level over the past three months by tracking glucose attached to red blood cells. |
| Fasting blood sugar test | Below 100 mg/dL | 100 to 125 mg/dL | 126 mg/dL or higher | Your blood is taken first thing in the morning after you’ve avoided eating overnight, and it requires a follow-up A1c test if elevated. |
| Random blood sugar test | N/A | N/A | 200 mg/dL or higher | This blood sample is drawn at a random time, regardless of meals, which requires a follow-up A1c test if elevated. |
| Oral glucose tolerance test for gestational diabetes | Below 140 mg/dL after one hour | 140 to 189 mg/dL | 190 mg/dL or higher at one hour | One hour after drinking a glucose solution, a lab technician checks your glucose levels. Borderline results require a follow-up three-hour test with three blood draws. |
Treatment and Medical Management
Healthcare providers tailor treatments and medical management for the specific type of diabetes and the individual’s health needs.
Insulin
Insulin is an injectable peptide hormone that mimics the hormone naturally produced in the pancreas to regulate blood sugar.
Insulin treatments for diabetes may include:
| Insulin Type | Example | Onset and Peak |
| Fast-acting | Humalog | Onset within 15 minutes and peaks an hour after injection, lasts up to four hours |
| Intermediate-acting | NPH or Humulin N | Onset within one to three hours after injection, reaches peak effectiveness between four and eight hours, lasts up to 12 hours |
| Long-acting insulin | Glargine | Onset after an hour, lasts 24 hours or longer |
Insulin is a necessary and effective first-line treatment for Type 1 diabetes. People with Type 2 and gestational diabetes, however, often produce some insulin in their body, so they may not need insulin injections as part of their disease management regimen.
Noninsulin oral medications
Metformin is often the first drug prescribed for those with Type 2 diabetes and is sometimes prescribed for those with prediabetes. Metformin improves the body’s efficiency with the insulin that it does make.
Other medications that may help people with Type 2 diabetes lower their blood glucose levels include:
— Alpha-glucosidase inhibitors
— Biguanides (including metformin)
— Bile acid sequestrants
— Dopamine-2 agonists
— DPP-4 inhibitors
— Meglitinides
— SGLT2 inhibitors
— Sulfonylureas
— Thiazolidinediones
— Oral combination therapy
GLP-1s and dual GIP/GLP-1 agonists
The biggest recent advancement in treatment of Type 2 diabetes is more effective, long-acting GLP-1 and dual GIP/GLP-1 receptor agonists, Goddard says.
GLP-1 medications, such as semaglutide (Ozempic and Wegovy) and dual GIP/GLP-1 agonists tirzepatide (Mounjaro and Zepbound), are also injectable peptides, like insulin. These medications stimulate insulin production, slow gastric emptying and help regulate appetite.
“They not only lower blood sugar and help with weight gain, they also reduce the risk of cardiovascular disease, kidney disease and liver disease, all of which people with Type 2 diabetes are at increased risk for,” Goddard adds.
Blood glucose monitoring technology
People with diabetes need to monitor their blood sugar levels to manage their disease.
The most cost-effective and common method is through a glucose meter, or glucometer. After you draw blood with a small finger prick, the glucometer measures your current blood sugar level.
There are also continuous glucose monitors, such as the Dexcom or FreeStyle machines, which are closed-loop systems that communicate with insulin pumps.
“These monitors adjust the rate at which insulin is given. It has been a huge step forward and uses technology to do a lot of work that patients and doctors used to do manually,” Goddard says.
Lifestyle Modifications and Prevention
Advanced medical technology and treatment are necessary for diabetes care, but lifestyle modifications and prevention strategies are still foundational for lowering the A1c naturally and protecting metabolic health.
The first step is creating goals for diabetes self-care, says Carole Jakucs, a board-certified diabetes nurse educator based in Los Angeles.
“We help patients identify what lifestyle habits they feel are important to change and what is doable and realistic for their lifestyle,” she explains.
Some of the goals that Jakucs suggests include:
— Exercise and physical activity: “One simple way to control postmeal blood glucose spikes is to take a 10-minute, moderate to brisk-paced walk after each main meal. If walking after each meal is not possible, then walking at least 15 minutes after the two largest meals or walking 30 minutes a day after the largest meal each day also helps,” she says. Generally, adults should aim for 30 minutes of aerobic activity five days per week.
— Dietary strategy and nutrition: Include lean protein with meals and snacks to delay gastric emptying, lessening your postmeal blood glucose spike. “Eating enough protein also helps to support muscle mass and increase satiety, which helps control appetite to prevent overeating,” Jakucs adds. Eating more fiber is also beneficial for blood sugar control and general health. If you are unsure what to eat, Jakucs recommends the “diabetes plate method”: Fill half your plate with nonstarchy vegetables, such as greens, broccoli or squash; fill one quarter with lean protein, such as chicken; and fill the last quarter of your plate with a high-fiber carbohydrate, such as brown rice or quinoa.
— Carbohydrate counting: Counting carbs is especially important for anyone who is on mealtime (bolus) insulin and whose doctor has prescribed an insulin-to-carb ratio for dosing their bolus insulin appropriately.
— Weight loss if overweight or obese: “We know that if a person loses at least 5% to 10% of their weight, if they are overweight or obese, (that) can help reduce their level of insulin resistance and increase insulin sensitivity. This helps to lower their blood glucose,” Jakucs says.
— Quality sleep and stress reduction: “Emotional and physical stress and lack of sleep raise blood glucose because these raise the level of cortisol, the stress hormone, which triggers more glucose release from the liver,” Jakucs says. Aim for at least seven hours of quality, restorative sleep each night.
Long-Term Complications and Outlook
Diabetes, when left untreated, can cause long-term complications throughout the body:
— Heart and blood vessel disease
— Nerve damage (neuropathy)
— Eye damage, including cataracts, glaucoma and blindness
— Skin and mouth conditions
— Pregnancy complications, including risk of miscarriage, stillbirth and birth defects
— Slow healing of cuts and blisters
— Alzheimer’s disease
— High blood pressure
Microvascular complications
Microvascular complications are when high blood sugar damages the body’s smallest blood vessels.
As glucose cells flow through the bloodstream, they injure the delicate linings of blood vessels. When glucose levels are consistently elevated, these vessels become weak and restrict blood flow. This can impact the eyes and the kidneys, which have vascular networks containing small capillaries and vessels.
Macrovascular complications
Diabetes also impacts larger blood vessels through inflammation and plaque buildup (atherosclerosis).
This effect causes narrowing and restriction of major vessels, blocking oxygen and leading to heart attack, stroke and peripheral artery disease.
Diabetic foot health
Food health is also a window into your overall diabetes management.
Because long-term elevated blood sugar damages both nerves and blood vessels, it damages the nerves and vessels in the feet. At the periphery of the body, the nerves in the feet are often the first to go, says Dr. Mikel Daniels, a board-certified podiatric surgeon and president and chief medical officer of WeTreatFeetPodiatry, with practices in Maryland, Washington, D.C. and Pennsylvania.
“They stop feeling pain, heat and pressure,” he adds. “I have patients who will walk in with a complaint of a blister that has opened into an ulcer through several layers of skin.”
Unmanaged diabetes can lead to:
— Absent pulses in the feet
— Shiny skin on the legs
— Thick nails
— Calluses and corns
— Skin ulcers
— Fungal infections in the toenails
Proper shoes, insoles, offloading (reducing pressure on the foot through special shoes, cushions or mobility devices) and diabetes management can change everything with your foot health, Daniels says.
To maintain your diabetic foot health, Daniels recommends checking your feet every day. Watch for:
— Color changes, such as redness, darkening or streaks traveling up the foot or leg
— Redness around a callus or wound
— Pale or bluish color
— Swelling
— Warmth
— Skin breakdown, such as cracks, blisters or open areas, regardless of size
— Drainage, such as blood or fluid
— Odor
— Temperature changes, such as one foot warmer than the other
— Nail and skin changes, such as thick, crumbly nails, fissures in the heel, white or soggy skin or dry and cracked skin
— Changes in shape, such as toes drifting or arch collapsing
If you notice any of these changes during an at-home foot check, message your primary care provider (PCP) or podiatrist right away. Even a small change, if left untreated, can lead to loss of function in the foot and sometimes require amputation.
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Diabetes Guide: Types, Symptoms, Causes and Treatments originally appeared on usnews.com
Update 08/12/26: This story was previously published at an earlier date and has been updated with new information.
