Type 2 Diabetes: Symptoms, Causes, and Treatment

Type 2 diabetes occurs when your body can't properly use insulin or doesn't make enough. This causes high blood sugar. While it can't be cured, lifestyle changes and medications help manage it. See your doctor if you notice frequent urination, unusual thirst, or tiredness that won't go away.

In plain words

Type 2 diabetes happens when your body has trouble using insulin properly or doesn't make enough insulin. Insulin helps your body use sugar for energy. Without enough insulin, sugar builds up in your blood. This can make you feel very thirsty, tired, and cause you to pee a lot. It usually develops slowly over many years. People who are overweight or have family members with diabetes are more likely to get it. You can't cure type 2 diabetes, but with healthy eating, exercise, and sometimes medicine, most people can manage it well. See a doctor if you notice signs like being extra thirsty, going to the bathroom often, or feeling very tired.

What is Type 2 Diabetes: Symptoms, Causes, and Treatment?

Symptoms

Early symptoms

Increased thirst: Drinking more water than usual because your body is trying to flush out extra sugar through urine. (2) (5)
Frequent urination: Needing to urinate more often, especially at night, as your kidneys work to remove excess glucose. (2) (7)
Fatigue: Feeling unusually tired because your cells aren't getting enough glucose for energy. (2)
Blurred vision: High blood sugar can cause the lenses in your eyes to swell, changing how you see. (5)
Slow-healing sores: High glucose levels make it harder for your body to fight infections and heal wounds. (7)

Serious or emergency symptoms

Confusion or dizziness: Very high blood sugar can affect brain function, making it hard to think clearly. Seek medical help immediately. (2)
Fruity-smelling breath: This can signal diabetic ketoacidosis (DKA), a dangerous complication when your body burns fat instead of glucose. Go to the emergency room or call emergency services right away. (2)

Causes

Primary causes

Insulin resistance: Your body's cells don't respond properly to insulin, so sugar builds up in your blood instead of being used for energy. (1)
Not enough insulin production: Over time, the pancreas can't keep up with the demand for insulin caused by insulin resistance. (1)

Risk factors

Overweight or obesity

Excess body fat, especially around the belly, makes cells more resistant to insulin. (1) (8)

Physical inactivity

Exercise helps control weight and makes cells more sensitive to insulin. (1)

Family history

Having a parent or sibling with type 2 diabetes increases your risk. (1)

Diagnosis

Doctors use blood tests to check for type 2 diabetes. The most common are the fasting plasma glucose test (fasting for at least 8 hours), A1C test (average blood sugar over 2-3 months), and oral glucose tolerance test (checks blood sugar before and after drinking a sweet drink). You'll need two abnormal results to confirm the diagnosis. Your doctor will review your medical history and risk factors too.

HbA1c test

Measures average blood sugar levels over the past 2-3 months. An A1C of 6.5% or higher suggests diabetes. (3) (5)

Fasting plasma glucose test

Checks blood sugar after not eating for at least 8 hours. 126 mg/dL or higher indicates diabetes. (3)

Oral glucose tolerance test

Measures blood sugar before and 2 hours after drinking a sweet liquid. Used less often than A1C and fasting tests. (3)

Treatment

Medication options

Biguanides

Reduces glucose production by the liver and helps your body use insulin better. Often the first medication prescribed for type 2 diabetes. (4) (6)

Sulfonylureas

Stimulates pancreas to release more insulin. Can help lower blood sugar when diet and exercise aren't enough. (4)

DPP-4 inhibitors

Helps your body release insulin after meals by blocking the DPP-4 enzyme. Causes less weight gain than some other diabetes medications. (6)

Lifestyle and self-care

Healthy eating: Focus on non-starchy vegetables, whole grains, lean proteins, and healthy fats. The plate method (half plate non-starchy vegetables, quarter plate protein, quarter plate carbohydrates) helps portion control. Limit sugary drinks and processed foods. (4) (9)
Regular physical activity: Aim for at least 150 minutes per week of moderate exercise like brisk walking. Activity helps lower blood sugar and makes insulin work better. Even small amounts help. (4)
Weight management: If overweight, losing even 5-7% of your body weight can significantly improve blood sugar control. Your doctor can help set realistic weight goals. (6)
Routine blood sugar checks: Regular monitoring helps you see how food, activity, and medications affect your glucose levels. Discuss testing frequency with your doctor. (4)

Always discuss dosing and treatment changes with your own prescriber.

Possible complications

Heart disease and stroke: High blood sugar damages blood vessels over time, increasing risk of serious cardiovascular problems by 2-4 times. (4)
Kidney disease (nephropathy): Diabetes can damage the kidneys' filtering system, eventually leading to kidney failure and need for dialysis. (4)
Nerve damage (neuropathy): High glucose damages nerves, often starting with tingling or numbness in feet. Can also affect digestion and sexual function. (4)
Eye damage (retinopathy): Damaged blood vessels in the retina can lead to vision loss and blindness if untreated. (4)

When to see a doctor

Routine follow-up

Schedule a visit if you notice possible diabetes symptoms like frequent thirst, urination, or unexplained weight loss - especially if you have risk factors. (3)

Seek emergency care

Seek emergency care for severe symptoms like confusion, rapid breathing, or fruity breath odor - these could signify life-threatening diabetic ketoacidosis. (2)

Frequently asked questions

Can type 2 diabetes be reversed?

While type 2 diabetes can't be completely cured, significant weight loss and lifestyle changes may lead to remission where blood sugar returns to normal without medication. However, this requires ongoing healthy habits and monitoring, as risk always remains. Talk with your doctor about realistic goals for your situation. (6) (4)

What are the first signs of type 2 diabetes?

Early signs include increased thirst, frequent urination (especially at night), feeling unusually tired, blurred vision, and slow healing of cuts. Some people also experience unintended weight loss. These develop gradually, so people often don't notice for years. (2) (5)

What is a normal blood sugar level?

For most people without diabetes: Fasting (before eating) should be under 100 mg/dL. Two hours after starting a meal, under 140 mg/dL is normal. An A1C test result under 5.7% is normal. Your doctor can explain targets that are right for your situation and age. (3) (5)

What foods should diabetics avoid?

Limit: sugary drinks like soda and juice, processed grains like white bread and white rice, fried foods high in unhealthy fats, and candy/desserts high in simple sugars. Focus on fiber-rich vegetables, whole grains, lean proteins and healthy fats like those in nuts and avocados. Portion control is key. (9)

Is type 2 diabetes genetic?

Genetics plays a strong role - having a parent or sibling with type 2 diabetes increases your risk 2-6 times. However, lifestyle factors like weight and activity determine whether inherited risk turns into actual disease. Even with genetic risk, healthy habits can delay or prevent onset. (1)

References

CDC — About Diabetes source 1
CDC — Diabetes Symptoms source 2
CDC — Diagnosing Diabetes source 3
CDC — Managing Diabetes source 4
NHS — Type 2 diabetes source 5
NHS — Type 2 diabetes treatment source 6
MedlinePlus — Type 2 Diabetes source 7
WHO — Diabetes fact sheet source 8
ADA — Eating Well source 9