Type 2 Diabetes: Symptoms, Causes, Diagnosis, and Treatment

Quick answer

What Is Type 2 Diabetes?

Type 2 diabetes is a common type of diabetes in which the body becomes less sensitive to insulin and gradually produces less of it. Often without symptoms at first, it increases the risk of heart disease, stroke, and kidney problems.

Sources

Signs That Need Urgent Help

Extreme thirst, a very dry mouth, and frequent urination for several days
Confusion, extreme sleepiness, or difficulty waking up
Nausea, vomiting, abdominal pain, or fast and deep breathing
Shaking, cold sweats, a pounding heart, or confusion because blood sugar is too low
Pain or pressure in the chest, shortness of breath, or cold sweats
Sudden facial drooping, weakness in an arm or leg, or slurred speech
A foot wound that turns black, swells, smells bad, or comes with a fever

If these signs appear, go to the nearest emergency department right away or call Heart Attack Center 1500 258.

Urgency note: Type 2 diabetes is usually managed through regular checkups. However, very high blood sugar with intense thirst and confusion, very low blood sugar, or signs of a heart attack or stroke need immediate help.

01 / Understanding the condition

About Type 2 Diabetes

Type 2 diabetes is the type of diabetes mellitus that affects most people with diabetes, about 90 to 95 percent. In this condition, the pancreas still makes insulin, but the muscle, liver, and fat cells do not respond to it well. This is called insulin resistance. To compensate, the pancreas works harder, but over time insulin production declines and blood sugar rises.

Type 2 diabetes develops slowly. Before it appears, many people go through a stage called prediabetes, when blood sugar is above normal but has not yet reached the diabetes threshold. Because it often causes no symptoms, many people only find out from a routine checkup or after complications appear. Asian people, including Indonesians, tend to develop type 2 diabetes at a younger age and a lower body weight than European populations, because fat builds up more easily in the abdomen and inside the liver.

Why the Heart Is Also Affected

Type 2 diabetes rarely comes alone. It often occurs together with high blood pressure, abnormal cholesterol, and excess belly fat, a cluster of conditions known as metabolic syndrome. This combination damages the inner lining of the blood vessels and speeds up atherosclerosis, the buildup of plaque in the artery walls. As a result, the risk of coronary artery disease, heart attack, stroke, and narrowing of the leg arteries increases. Diabetes also raises the risk of heart failure, even before the coronary arteries narrow. In some people, a heart attack feels vague, for example only shortness of breath or weakness.

Treatment That Protects the Heart

Managing type 2 diabetes today is not only about lowering blood sugar. ADA and ESC guidelines recommend that doctors choose medicines based on the condition of the heart and kidneys. Some classes of medicines, such as SGLT2 inhibitors and GLP-1 receptor agonists, have been shown to lower the risk of heart events or hospitalization for heart failure in certain groups. This treatment is complemented by controlling blood pressure, cholesterol, and weight, and by quitting smoking. Targets and medicine choices are decided together with your doctor based on your situation.

The good news is that lifestyle changes from an early stage can slow the course of the disease. In some people, substantial weight loss even brings blood sugar back to normal without medicine for a period of time, which is called remission.

02 / Understanding the condition

Symptoms to Recognize.

Common Symptoms

Many people have no symptoms for years. Regular blood sugar checks help find it earlier.

Frequent urination, especially at night
Frequent thirst and a dry mouth
Tiring easily and feeling sleepy
Blurred vision
Wounds that are slow to heal, or repeated infections of the skin, gums, and urinary tract
Tingling, numbness, or a burning feeling in the feet and hands
Thickened, darkened skin on the neck or in the armpit folds

Symptoms in Older Adults

In older adults, the typical symptoms are often less noticeable, and low blood sugar caused by medicines also happens more easily.

Vague complaints such as weakness, reduced appetite, or weight loss
Becoming dehydrated easily because the sense of thirst is reduced
New confusion or memory decline
Falling more often or difficulty walking because the feet feel numb
Loss of bladder control or frequent urination at night

Not everyone has the same symptoms. If symptoms keep coming back or get worse, get checked.

03 / Understanding the condition

What Causes This Condition?

Insulin resistance: muscle, liver, and fat cells respond poorly to insulin
A gradual decline in insulin production by the beta cells of the pancreas
Excess fat, especially in the abdomen and inside the liver, which interferes with how insulin works
The liver releasing too much sugar into the blood, especially during fasting and at night
A combination of inherited factors with a high-calorie diet and too little physical activity

04 / Understanding the condition

Who Is at Higher Risk?

Lifestyle

Being overweight or obese, a large waist, too little physical activity, frequent sugary drinks and processed foods, too little sleep, and smoking.

Medical

Prediabetes, hypertension, low HDL cholesterol or high triglycerides, heart disease, fatty liver, polycystic ovary syndrome, and a history of gestational diabetes.

Genetic

A parent or sibling with type 2 diabetes. Asian people, including Indonesians, can develop diabetes at a lower body weight than European populations.

Age

Risk increases after age 35 to 40. Type 2 diabetes is now also increasingly found at younger ages, including in teenagers with obesity.

Other

Long-term use of certain medicines such as corticosteroids, and prolonged stress that disrupts eating and sleeping patterns.

Groups at Higher Risk

People with Excess Weight: A body mass index of 23 or more in Asian people, or a large waist, is closely linked to insulin resistance.
Age 35 or Older: ADA guidelines recommend screening for all adults starting at age 35, repeated at least every three years if the results are normal.
People with Prediabetes: Blood sugar is above normal but not yet at the diabetes level. Without lifestyle changes, many go on to develop type 2 diabetes.
People with Heart Disease or Hypertension: The 2023 ESC guidelines recommend a fasting blood sugar or HbA1c test for everyone with heart and blood vessel disease.
Women with a History of Gestational Diabetes: The risk of type 2 diabetes remains high for years after giving birth, so blood sugar needs to be rechecked regularly.

Having a risk factor does not mean a person will definitely develop this condition.

05 / Understanding the condition

How Is It Diagnosed?

Because it often causes no symptoms, type 2 diabetes is frequently found through screening. The diagnosis is made when fasting blood sugar, HbA1c, or an oral glucose tolerance test (OGTT) reaches the diabetes threshold, usually based on two high results. A high random blood sugar together with typical symptoms is also enough for a diagnosis.

After the diagnosis, your doctor assesses how far diabetes has affected your body and estimates your cardiovascular risk. Initial checks include blood pressure, weight and waist circumference, cholesterol profile, kidney function and urine albumin, liver function, eyes, and feet. The 2023 ESC guidelines recommend an ECG for people with diabetes who have hypertension or suspected heart disease, and asking about heart failure symptoms at every visit. If you have complaints such as chest pain or shortness of breath during activity, your doctor may continue with echocardiography, an exercise stress test, or coronary CT. This assessment helps choose diabetes medicines that also protect the heart and kidneys.

Diabetes Screening
Testing for people at risk who have no symptoms, recommended for all adults starting at age 35, and earlier if risk factors are present.
Blood Sugar Test
A fasting blood sugar of 126 mg/dL or more, or 200 mg/dL or more two hours into an OGTT, indicates diabetes. A fasting blood sugar of 100 to 125 mg/dL is considered prediabetes.
HbA1c Test
A value of 6.5 percent or more indicates diabetes, while 5.7 to 6.4 percent is considered prediabetes. It is also used to monitor treatment.
Urine Protein Test
Urine albumin and kidney function are checked at diagnosis and every year to detect kidney and blood vessel damage early.
Cholesterol and Lipid Profile Screening
Measures LDL, HDL, and triglycerides as the basis for cholesterol targets that match your level of risk.
Individual Heart Risk Screening
Estimates your risk of heart attack and stroke over the next 10 years, for example with SCORE2-Diabetes, to decide how intensive treatment should be.
Electrocardiogram (ECG)
Recommended if you have hypertension or suspected heart disease, to look for rhythm problems or signs of an earlier heart attack that went unnoticed.

06 / Understanding the condition

Treatment Options.

Treatment is decided by a doctor after an assessment. The categories below can help you follow the conversation with your doctor.

Healthy Eating and Weight Loss

A balanced eating pattern with measured carbohydrate portions. Losing 5 percent or more of your body weight helps improve blood sugar, blood pressure, and cholesterol.

Regular Physical Activity

About 150 minutes of aerobic activity per week plus strength training 2 to 3 times a week improves the body's sensitivity to insulin. Talk to your doctor first if you have heart disease.

Blood Sugar-Lowering Medicines

Your doctor chooses from medicine classes such as metformin, SGLT2 inhibitors, GLP-1 receptor agonists, DPP-4 inhibitors, or sulfonylureas, often in combination, based on your condition.

Medicines That Protect the Heart and Kidneys

For people with heart disease, heart failure, kidney disease, or high risk, guidelines recommend SGLT2 inhibitors or GLP-1 receptor agonists, which have been shown to reduce heart events, regardless of the HbA1c value.

Insulin Therapy

Needed when blood sugar stays high despite other medicines, during a serious illness, or during pregnancy. The type and schedule are determined by your doctor.

Blood Pressure and Cholesterol Control

Statins and blood pressure medicines are often needed to lower the risk of heart attack and stroke. The targets are set by your doctor based on your level of risk.

Metabolic Surgery

Surgery on the stomach or intestines may be considered for people with severe obesity whose blood sugar is hard to control, after evaluation by a team.

Whether a test or therapy is suitable and available needs to be confirmed with your care team.

07 / Understanding the condition

Complications to Watch For.

Coronary Artery Disease and Heart Attack

Plaque in the coronary arteries narrows blood flow to the heart muscle. In people with diabetes, a heart attack sometimes feels like only shortness of breath or weakness. Covered on the Coronary Artery Disease page.

Heart Failure

Diabetes can make the heart muscle stiff or weak. Shortness of breath during activity, tiring easily, and leg swelling should be checked. Covered on the Heart Failure page.

Stroke

Damage to the blood vessels of the brain and neck increases the risk of stroke caused by a blockage. Covered on the Stroke page.

Peripheral Artery Disease and Diabetic Foot

The leg arteries narrow and the foot nerves become less sensitive, so small wounds easily become infected and are slow to heal. Covered on the Peripheral Artery Disease page.

Diabetic Kidney Disease

Small blood vessels in the kidneys are damaged, albumin leaks into the urine, and kidney function gradually declines. Covered on the Chronic Kidney Disease page.

Diabetic Retinopathy and Neuropathy

Damage to the blood vessels of the retina can affect vision, while nerve damage causes tingling, numbness, or pain in the feet and hands.

Hyperosmolar Hyperglycemic State

Very high blood sugar with severe dehydration, often triggered by an infection or another illness, especially in older adults. It causes confusion that can progress to reduced consciousness and needs immediate treatment.

08 / Understanding the condition

What Can You Do?

If you are overweight, gradually lose about 5 to 7 percent of your body weight
Stay active for about 150 minutes per week and cut down on long periods of sitting
Replace sugary drinks with water; eat more vegetables, legumes, and whole grains
Quit smoking and get enough sleep every night
Have your blood sugar checked starting at age 35, or earlier if you have risk factors
If you have prediabetes, join a lifestyle change program and get rechecked every year
Women with a history of gestational diabetes need regular blood sugar checks

09 / Understanding the condition

When Should You See a Doctor?

See a doctor for a blood sugar test if you have risk factors, even if you feel healthy. People with type 2 diabetes need scheduled checkups, and sooner if their symptoms change. If chest pain, signs of stroke, or reduced consciousness appear, go to the emergency room right away.

Frequent thirst, frequent urination, blurred vision, or wounds that are slow to heal
Age 35 or older, being overweight, or having a family member with diabetes
Blood sugar or HbA1c that has not yet reached the agreed target
Blood sugar that often drops too low after taking medicine
Shortness of breath during activity, tiring easily, palpitations, or leg swelling
Tingling, numbness, or sores on the feet

Don't Wait in an Emergency.

If symptoms are severe or come on suddenly, go to the nearest emergency department right away or call Heart Attack Center 1500 258, rather than waiting for an appointment.

10 / Common questions

Questions You May Have.

Frequently asked questions about type 2 diabetes and heart health.

Can type 2 diabetes be cured?

Type 2 diabetes is usually a long-term condition. However, in some people, especially in the early years, substantial weight loss can bring blood sugar back to normal without medicine. This is called remission rather than a cure, because blood sugar can rise again if weight is regained. HbA1c, blood pressure, and cholesterol still need to be checked regularly.

Why is type 2 diabetes closely linked to heart disease?

High blood sugar, high blood pressure, and abnormal cholesterol, which often occur together, damage the blood vessels and speed up plaque buildup. The good news is that a large Swedish study in 2018 showed that people with type 2 diabetes whose blood sugar, blood pressure, LDL cholesterol, and urine albumin were under control, and who did not smoke, had a risk of heart attack and stroke close to that of people without diabetes.

Do I have to start insulin right away?

Not always. Many people with type 2 diabetes start treatment with lifestyle changes and oral medicines or non-insulin injections. Insulin may be needed from the start if blood sugar is very high or symptoms are severe, and some people need it after many years because the body's own insulin production keeps declining. Using insulin is not a sign of failure but a way to keep blood sugar under control.

Do diabetes medicines damage the kidneys?

Diabetes medicines taken as your doctor advises do not damage the kidneys. In fact, it is uncontrolled blood sugar and blood pressure that damage the kidneys. Some classes of medicines, such as SGLT2 inhibitors, have even been shown to slow the decline in kidney function. Your doctor checks your kidney function regularly and adjusts the type or dose of medicine if it declines. Do not stop your medicines on your own out of worry.

If my blood sugar is already normal, can I stop taking my medicine?

Do not stop on your own. Normal blood sugar often shows that the medicine is working, and stopping it can make blood sugar rise again. In addition, some medicines are given to protect the heart and kidneys, not only to lower blood sugar. If you feel your medicine could be reduced, for example after losing a lot of weight, talk with your doctor so the change is made safely.

How often do I need to check my HbA1c?

ADA guidelines recommend an HbA1c test at least twice a year if your blood sugar is stable and on target. If your treatment has just been changed or the target has not been reached, HbA1c is usually checked every three months. Self-monitoring of blood sugar at home or a glucose sensor can complement this, especially if you use insulin or medicines that can make blood sugar drop too low.

Sources and Medical Review

Translated from the Indonesian edition medically reviewed by dr. Debby C. Soemitha, Sp.PD.

Sources as cited in the Indonesian edition.

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The information on this page is for educational purposes and does not replace medical consultation, diagnosis, or treatment. For any health concerns, please consult a doctor directly.

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