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Being overweight or having excess abdominal fat: Excess body fat, particularly around the abdomen, is associated with insulin resistance.
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Having a family history of diabetes: A parent or sibling with type 2 diabetes can increase your risk.
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Being physically inactive: Limited physical activity can contribute to insulin resistance.
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Getting older: The risk generally increases with age, although type 2 diabetes is increasingly diagnosed in younger adults.
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Having high blood pressure: Hypertension often occurs alongside other metabolic risk factors.
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Having abnormal cholesterol or triglyceride levels: These changes may be part of a broader pattern of metabolic dysfunction.
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Having a history of gestational diabetes: Women who developed diabetes during pregnancy have a higher risk of developing type 2 diabetes later.
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Having polycystic ovary syndrome (PCOS): PCOS is associated with an increased risk of insulin resistance and type 2 diabetes.
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Having prediabetes: Blood glucose levels that are higher than normal but not yet in the diabetes range indicate an increased risk.
Having one or more risk factors does not mean that someone will definitely develop diabetes. It does mean that discussing appropriate screening with a healthcare professional is worthwhile.
How Is Diabetes Diagnosed?
Symptoms can raise suspicion, but a blood test is needed to establish a diagnosis.
Several laboratory tests are commonly used.
1. A1C Test
The A1C test measures the average blood glucose level over approximately the previous two to three months.
It does not usually require fasting.
Common diagnostic thresholds for nonpregnant adults are:
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Below 5.7%: Normal range.
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5.7% to 6.4%: Prediabetes range.
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6.5% or higher: Diabetes range.
A result in the diabetes range generally needs confirmation with a second abnormal test unless the person has clear symptoms and a sufficiently high blood glucose result.
Certain conditions, including some types of anemia, hemoglobin disorders, pregnancy, and recent blood loss, can affect the accuracy of A1C testing.
2. Fasting Plasma Glucose Test
This test measures blood glucose after the person has not eaten or consumed anything containing calories for at least eight hours.
Typical diagnostic thresholds are:
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Below 100 mg/dL: Normal range.
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100–125 mg/dL: Prediabetes range.
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126 mg/dL or higher: Diabetes range.
A result in the diabetes range generally requires confirmation unless the clinical circumstances make the diagnosis clear.
3. Oral Glucose Tolerance Test
This test measures how the body responds to a specific amount of glucose.
After an initial fasting blood sample, the person drinks a glucose-containing liquid. Blood glucose is measured again two hours later.
For nonpregnant adults, the two-hour results are generally interpreted as:
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Below 140 mg/dL: Normal range.
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140–199 mg/dL: Prediabetes range.
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200 mg/dL or higher: Diabetes range.
This test is also used in specific pregnancy-related screening situations, although the testing protocol and diagnostic thresholds may differ.
4. Random Plasma Glucose Test
A random blood glucose test can be performed at any time, regardless of when the person last ate.
A result of 200 mg/dL or higher, together with classic symptoms of diabetes or a hyperglycemic crisis, can establish the diagnosis in the appropriate clinical setting.
A home glucose meter can help monitor blood sugar, but it should not be used as the sole method for diagnosing diabetes.
What Happens If Diabetes Is Not Treated?
Persistently high blood glucose can gradually damage different parts of the body.
The complications may not appear immediately, which is one reason some people underestimate the condition.
However, long-term uncontrolled diabetes can increase the risk of several serious health problems.
Heart and Blood Vessel Disease
Diabetes increases the risk of cardiovascular disease, including heart attacks, strokes, and problems involving blood circulation.
High blood glucose can contribute to damage in blood vessels, while diabetes frequently occurs alongside high blood pressure and abnormal cholesterol levels.
Managing all these risk factors is important for protecting cardiovascular health.
Kidney Damage
The kidneys contain tiny blood vessels that filter waste products from the blood.
Over time, diabetes can damage these structures and lead to diabetic kidney disease.
Early kidney damage may produce no noticeable symptoms. This is why people with diabetes are commonly advised to undergo regular urine and blood tests to assess kidney function.
Nerve Damage
Diabetic neuropathy can cause pain, tingling, numbness, and reduced sensation.
When protective sensation is lost, minor foot injuries may go unnoticed. These injuries can develop into ulcers or infections if not recognized and treated.
Eye Problems
Diabetes can damage the blood vessels in the retina and increase the risk of diabetic retinopathy.
It can also increase the likelihood of developing cataracts and glaucoma.
Regular comprehensive eye examinations are important even when vision appears normal.
Increased Risk of Infections
High blood glucose can make it more difficult for the immune system to respond effectively to certain infections.
Skin infections, urinary tract infections, and fungal infections may occur more frequently in some people with poorly controlled diabetes.
The good news is that early diagnosis and appropriate management can substantially reduce the risk of many complications.
Can Diabetes Be Prevented or Delayed?
Type 1 diabetes is generally not preventable through ordinary lifestyle changes.
However, many cases of type 2 diabetes can be prevented or delayed, particularly among people with prediabetes or other risk factors.
Several lifestyle habits can make a meaningful difference.