What is Type 2 Diabetes?

Type 2 diabetes is a chronic condition that affects how your body uses glucose (blood sugar) for energy. It's the most common form of diabetes, making up 90 to 95% of all diagnosed cases. The Centers for Disease Control and Prevention (CDC) estimates that nearly 16% of U.S. adults are living with diabetes, and most of them have type 2.

For decades, T2D was seen mostly in people over 45. Today, it’s showing up more often in younger adults, teens, and even children. That shift highlights an important fact: type 2 diabetes can affect people at any age.

How Type 2 Diabetes Develops

T2D occurs when the body cannot properly use insulin, or when the pancreas does not make enough insulin to keep blood sugar levels in balance.

Insulin’s role:

• Insulin is a hormone made in the pancreas, an organ located just behind the stomach.
• Its job is to act like a “key,” allowing glucose (sugar from food) to move out of the bloodstream and into the cells for energy.

What goes wrong in T2D:

• In T2D, the body’s cells become insulin resistant, meaning they no longer respond to insulin the way they should.
• At first, the pancreas tries to “keep up” by making more insulin. This can hold blood sugar levels close to normal for a while.
• Over time, the pancreas becomes overworked and begins to wear out. It can’t produce enough insulin, leaving excess sugar in the bloodstream.
• The result is chronically high blood sugar, which can damage blood vessels and organs if left unmanaged.

Symptoms of Type 2 Diabetes

The early symptoms of type 2 diabetes can develop slowly and be easy to miss. Many people don't notice them at first, but over time, they can become more pronounced.

Common signs:

• Constant thirst and dry mouth
• Frequent urination, especially at night
• Ongoing fatigue and low energy
• Blurry vision that comes and goes
• Cuts or sores that heal slowly
• Tingling, burning, or numbness in the hands and feet

Serious warning signs:

When blood sugar levels get very high, more severe symptoms can appear. These require immediate medical attention, as they may indicate an emergency like diabetic ketoacidosis (DKA) or hyperosmolar hyperglycemic state (HHS). Both are life-threatening conditions.

• Extreme thirst and frequent urination that won’t stop
• Severe fatigue that makes daily activities difficult
• Sudden, unexplained weight loss
• Rapid worsening of vision (sometimes double vision)
• Nausea, vomiting, or abdominal pain
• Shortness of breath, fruity-smelling breath, or sudden confusion

If you experience these symptoms, seek emergency care right away.

Risk Factors for Developing Type 2 Diabetes

Several factors can increase your risk of developing type 2 diabetes. Some risks are inherited, while others are linked to lifestyle or medical history. Having a risk factor doesn't mean you will get diabetes, but it does increase your chances.

Risk factors you cannot change:

• Age: risk increases after 45
• Family history: having a parent, brother, or sister with diabetes

Risk factors you can change or manage:

• Carrying extra weight, especially around the waist
• Lack of regular physical activity
• High blood pressure
• High cholesterol or high triglycerides
• History of gestational diabetes (diabetes during pregnancy)
• Polycystic ovary syndrome (PCOS) in women

The more risk factors you have, the higher your likelihood of developing type 2 diabetes. For example, someone with both a family history and excess weight faces more risk than someone with only one of those factors.

How is Type 2 Diabetes Diagnosed?

Diagnosing type 2 diabetes requires blood tests that measure how your body handles sugar. Each test works a little differently, and in some cases, doctors may repeat a test to confirm the result.

Fasting Plasma Glucose (FPG):

• Blood is taken after at least 8 hours without eating.
• A result of 126 mg/dL or higher indicates diabetes.
• Often the first test ordered, since it’s simple and quick.

Oral Glucose Tolerance Test (OGTT):

• Blood is checked both before and 2 hours after drinking a sugary beverage.
• If your blood sugar reaches 200 mg/dL or higher after 2 hours, it points to diabetes.

Hemoglobin A1C (HbA1C):

• Shows your average blood sugar over the past 2–3 months.
• A reading of 6.5% or higher confirms diabetes.

Random Plasma Glucose Test:

• Can be done any time of day, whether you’ve eaten or not.
• If you have common symptoms (such as frequent urination, thirst, or unexplained hunger) and your blood sugar is 200 mg/dL or higher, that may be enough for a diagnosis.

Complications of Type 2 Diabetes

When blood sugar levels stay high for a long time, they can slowly damage different organs and systems throughout your body. This damage can happen quietly without obvious symptoms until it becomes more serious.

Areas most affected include:

• Heart and circulation: higher risk of heart attack, stroke, and high blood pressure
• Nerves: tingling, numbness, burning, or pain in hands and feet
• Kidneys: filters weaken, leading to kidney disease or failure in severe cases
• Eyes: damage to blood vessels in the retina can cause vision loss or blindness
• Skin: cuts, sores, and infections take longer to heal; certain skin conditions are more common
• Mouth: gum disease, cavities, and dry mouth occur more often
• Feet: poor circulation plus nerve damage means injuries may go unnoticed, raising the risk of serious infections

More Serious Outcomes

If diabetes remains uncontrolled, complications can become life-altering. These include:

• Permanent loss of vision
• Kidney failure requiring dialysis or transplant
• Amputations (toes, feet, or part of the leg)
• Major heart disease or stroke

Why Early Diagnosis Matters

If you notice symptoms that sound familiar, or if you know you have risk factors, the next best step is to talk with your doctor. A simple blood test can reveal if your blood sugar is too high. Even if you feel fine, it’s worth checking, since type 2 diabetes often develops silently.

Detecting the condition early makes a big difference. The sooner you know what’s happening in your body, the sooner you can take steps to manage blood sugar, reduce risks, and protect your long-term health.