Type 2 diabetes can develop with few or no symptoms. Learn the early signs of diabetes, who should be tested and how a simple blood test can provide answers.
Diabetes is common, but its early signs can be easily overlooked. Increased thirst, fatigue or frequent urination may be mistaken for stress, aging or a busy schedule, but it could actually be a sign of pre-diabetes or diabetes progression. However, many people with pre-diabetes or type 2 diabetes have few or no symptoms at all.
The good news is that diabetes can often be detected with a simple blood test. The earlier the diagnosis, the better the chance of slowing disease progression and starting appropriate treatment.
What is Diabetes?
When you eat, your body breaks down food into glucose, a type of sugar that provides energy to your cells. Insulin, a hormone made by the pancreas, helps glucose move from your bloodstream into your cells.
Diabetes develops when your body does not make enough insulin, does not use insulin effectively or both. As a result, glucose builds up in the blood.
There are several types of diabetes:
- Type 1 diabetes: The immune system attacks the cells in the pancreas that make insulin. As a result, the body makes little or no insulin. Type 1 diabetes can develop at any age.
- Type 2 diabetes: The body does not use insulin effectively and, over time, may not make enough. It is the most common type of diabetes.
- Gestational diabetes: Diabetes that develops during pregnancy.
What is Prediabetes?
Prediabetes means blood sugar levels are higher than normal, but not yet high enough to meet the criteria for diabetes. It usually causes no symptoms and is often discovered during routine bloodwork. Prediabetes and insulin resistance are related, but they are not the same thing. Learn more about the difference between insulin resistance and prediabetes and why it matters.
An A1C of 5.7 percent to 6.4 percent or a fasting blood glucose of 100 to 125 mg/dL is in the prediabetes range.
Prediabetes increases the risk of developing type 2 diabetes, but it does not mean diabetes is inevitable. Working with your health care provider on physical activity, nutrition, weight management when appropriate and other healthy habits can help lower your risk.
What are the Early Signs of Diabetes?
Diabetes symptoms can vary from person to person, and many of these symptoms can have other causes. Having one symptom does not necessarily mean you have diabetes.
However, if you notice several of the following symptoms — particularly if they are new or persistent — it is worth talking with your health care provider.
Increased Thirst and Frequent Urination
When blood sugar levels are high, the kidneys work to remove extra glucose from the blood. This can cause you to urinate more often and lose fluids, leading to increased thirst.
Increased Hunger
Some people with diabetes feel hungry even after eating. This can happen when glucose is not moving into cells effectively to provide energy.
Unexplained Weight Loss
Losing weight without trying can be a sign of diabetes. It is more common with type 1 diabetes, when symptoms may develop quickly, but it can also occur with type 2 diabetes.
Fatigue
Feeling tired from time to time is normal. Persistent or unusual fatigue, particularly when it occurs with other symptoms of diabetes, is worth discussing with your provider.
Blurred Vision
High blood sugar can cause temporary changes in the eye that affect your ability to see clearly.
Slow-Healing Cuts or Sores
Over time, high blood sugar can affect blood vessels and nerves, which may make it harder for the body to heal wounds.
Frequent Infections
People with diabetes may be more likely to develop certain infections, including urinary tract, yeast or skin infections.
Numbness or Tingling
Numbness, burning or tingling in the hands or feet can occur when diabetes affects the nerves. This is generally associated with longer-term high blood sugar and can have many other causes.
Can You Have Diabetes Without Symptoms?
Yes. Type 2 diabetes can develop gradually and may cause few or no noticeable symptoms.
This is one reason that regular health screenings are important. Blood sugar can rise slowly over time, and subtle symptoms may be easy to miss.
According to the Centers for Disease Control and Prevention (CDC), people with symptoms should be tested, while some people without symptoms may also need testing based on their risk factors.
Detecting diabetes early gives you and your health care team more time to manage blood sugar and reduce the risk of complications affecting the heart, kidneys, eyes and nerves.
Who is at Risk for Type 2 Diabetes?
Your risk of developing type 2 diabetes may be higher if you have:
- A family history of type 2 diabetes
- Prediabetes
- High blood pressure
- A history of gestational diabetes
- Low levels of physical activity
- Older age
- Certain racial or ethnic backgrounds
Having one or more risk factors does not mean you will develop diabetes. People without obvious risk factors can develop diabetes, too.
Talk with your primary care provider about whether diabetes screening is appropriate for you and how often you should be tested.
How is Diabetes Diagnosed?
Diabetes is diagnosed with blood tests. Your provider may recommend different tests depending on your symptoms, health history and risk factors.
Common tests include:
- A1C test: Measures your average blood sugar over the past two to three months. You do not need to fast before an A1C test.
- Fasting plasma glucose test: Measures your blood sugar after fasting for at least eight hours.
- Oral glucose tolerance test: Measures blood sugar before and after you drink a glucose-containing liquid. This test is used more often in certain situations, including pregnancy.
- Random plasma glucose test: Measures blood sugar at any time of day and may be used when someone has symptoms of diabetes.
For nonpregnant adults, an A1C of 6.5 percent or higher or a fasting blood glucose of 126 mg/dL or higher is in the diabetes range.
A diagnosis is generally confirmed with repeat testing unless symptoms are clear. The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) provides more information about diabetes testing and diagnosis.
Home blood glucose meters can help people monitor blood sugar, but they are not used on their own to diagnose diabetes.
When Should You See a Doctor?
If you have symptoms of diabetes or are concerned about your risk, make an appointment with your primary care provider. Let your provider know which symptoms you’ve noticed, how long you’ve had them and whether diabetes runs in your family.
Do not wait for a routine appointment if you develop symptoms of diabetic ketoacidosis (DKA), a serious complication that can occur when there is not enough insulin. Warning signs can include nausea or vomiting, abdominal pain, extreme thirst, dehydration, trouble breathing, confusion or fruity-smelling breath. DKA requires urgent medical attention.
Can Type 2 Diabetes be Prevented?
Type 1 diabetes cannot currently be prevented. For type 2 diabetes, healthy lifestyle habits can help lower your risk or delay its onset.
For people who already have type 2 diabetes, healthy lifestyle changes and treatment can also improve blood sugar control. In some cases, people may be able to achieve remission.
Learn more about whether type 2 diabetes can be reversed and what remission means.
The Bottom Line
Diabetes does not always cause obvious symptoms, especially in its early stages. Increased thirst, frequent urination, unexplained weight loss, fatigue and blurred vision can be warning signs, but a blood test is the best way to determine whether you have diabetes or prediabetes.
If you have symptoms or risk factors, talk with your health care provider about whether you should be tested. Finding diabetes early can give you more time to manage your blood sugar and protect your health for years to come.
