Recognizing the Signs and Symptoms of Diabetes

About Diabetes Symptoms

A female doctor and a female diabetic patient

As a certified diabetes educator (CDE), I’ve often hear diabetes called a “silent” disease. Why?

Diabetes is a peculiar disease in that there is a myriad of symptoms, but those symptoms are typically not exhibited until blood sugar levels are grossly elevated. It is often termed as “silent” because when the disease could initially be diagnosed, there are rarely any symptoms.

That being said, it is also highly subjective to the patient. While there is a strict diagnostic criterion, which we’ll discuss in great detail, no two people are alike. What I mean by this is that patient A may have symptoms when their A1C has reached 7.8%, while patient B may not have symptoms until their A1C has reached 11.2%.

As a healthcare provider, when I say subjective, I mean that we have to take it for the patient’s word. So, if the patient says, “Well, I haven’t had any symptoms until three weeks ago!” that is what I have to believe – because every person is different.

Diagnostic Criteria for Diabetes

There are several ways that we can obtain a diabetes diagnosis, some of which are utilized more frequently than others.

The four options for diabetes diagnosis include:

  • A fasting plasma glucose level of greater than or equal to 126 mg/dL (7.0 mmol/L); fasting, in this case, means that the person should have had no caloric intake for at least eight hours.
  • A two-hour post-prandial glucose level of greater than or equal to 200 mg/dL (11.1 mmol/L) during an oral glucose tolerance test. During an oral glucose tolerance test, the person consumes 75 grams of anhydrous glucose, and the glucose level is checked two hours later.
  • An A1C level of greater than or equal to 6.5% (48 mmol/mol).
  • A random plasma glucose level of greater than or equal to 200 mg/dL (11.1 mmol/L), in individuals with symptoms of hyperglycemia.

Sometimes, a diagnosis of diabetes is obtained as a result of the patient going to their physician or emergency department due to symptoms that are suspicious of diabetes. At that time, one of these diagnostic tests may be performed.


At other times, diagnostic testing is performed as a result of routine screening, especially in the absence of symptoms.

Routine Screening for Diabetes

Physicians follow specific guidelines, as outlined by the American Diabetes Association (ADA), for routine screening for diabetes.

However, testing is done earlier in individuals who are overweight or obese, or who have the following risk factors:

  • Physical inactivity
  • History of cardiovascular disease
  • First-degree relative with diabetes
  • High-risk race or ethnicity (African-American, Latino, Native American, Asian American, Pacific Islander)
  • Having elevated cholesterol levels (HDL less than 35 mg/dL and/or triglycerides greater than 250 mg/dL)
  • Having hypertension (140/90 or on treatment for hypertension)
  • Women who have delivered a baby weighing over nine pounds or who have had gestational diabetes (GDM)
  • Having been diagnosed with pre-diabetes (an A1C greater or equal to 5.7% but less than 6.5%), impaired glucose tolerance, or impaired fasting glucose
  • Having certain conditions that are associated with insulin resistance (acanthosis nigricans, severe obesity, and polycystic ovarian syndrome)

Testing for diabetes in children is not routine. However, there are guidelines in place if a child is overweight and two or more of the following specific risk factors:

  • Has a family history of diabetes
  • Is a high-risk race or ethnicity
  • Has a maternal history of GDM during gestation
  • Exhibits signs of insulin resistance

Which almost brings us to the symptoms of diabetes. But first, it is important to understand how insulin works in the body – because when your body is not utilizing insulin correctly, your glucose levels skyrocket; the symptomology may make a bit more sense.

The Role of Insulin and Glucose

First of all, it is important to understand that insulin is a hormone. The pancreas produces it in response to an elevation of blood sugar levels (for example, when glucose is consumed or when the liver produces glucose).

When things are working as they should, the pancreas secretes insulin into the bloodstream in response to the elevation of blood sugar. It secretes the “right” amount, and this perfect amount allows the sugar (the glucose) to enter the red blood cells. The cells then transport the glucose where energy is needed (for example, the lungs, the brain, the muscles). This action lowers the blood sugar level.

When you have diabetes, your body may not be producing enough insulin, or you may be insulin resistant (or both!) and this “perfect dance” isn’t happening as it should. This causes elevated blood sugar levels – and eventually if left untreated, the symptoms of diabetes develop.

Everything You Need to Know About Diabetes Symptoms

As we’ve previously discussed, typically diabetes symptoms do not develop until blood sugar levels are very high.

In fact, some people can have diabetes for years before diabetes symptoms develop! On the next page, you can find a detailed description of each of the symptoms of diabetes.

Symptoms of diabetes may include:

  • Increased thirst
  • Frequent urination
  • Fatigue
  • Increased hunger
  • Weight loss
  • Blurred vision
  • Acanthosis nigricans
  • Slow-healing wounds

Next page: Learn more about the symptoms of diabetes in full detail and the complications of diabetes.

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