Type 1 Diabetes Signs and Symptoms

Type 1 diabetes is a chronic condition with symptoms that can appear suddenly. If left untreated, the condition can lead to serious complications. That’s why knowing the symptoms that may be a signal of type 1 diabetes is key.

Photo of a female doctor with a protective face mask checking her patient's blood glucose level
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Type 1 diabetes is a chronic condition in which the pancreas produces little to no insulin.

Insulin is a hormone that moves glucose, or blood sugar, from your blood to your cells. When it enters the cells, the glucose is used for energy. But the lack of insulin with type 1 diabetes means that glucose can't be moved into cells and instead builds up in the bloodstream, according to MedlinePlus.¹ This causes high glucose levels, leading to a variety of symptoms.

These symptoms can appear suddenly, developing within a few weeks or months, per the Centers for Disease Control and Prevention (CDC).² Typically, type 1 diabetes develops in children and young adults, but it is possible for someone of any age to experience the condition and its symptoms.

Although type 1 diabetes is a manageable condition, left untreated, the disease can cause complications. Therefore, the symptoms of type 1 diabetes should be taken seriously so that you can get evaluated, diagnosed, and treated in a timely manner.

Read on to learn about the symptoms of type 1 diabetes and when to contact your health care provider if you or a loved one is exhibiting any of the symptoms.

Signs and Symptoms of Type 1 Diabetes

There are several signs and symptoms that might indicate undiagnosed type 1 diabetes:

Frequent Urination

An increased need to urinate can be a sign of type 1 diabetes. This is especially true for children and adolescents, according to a 2014 article in the Lancet, though possible for adults as well.³

Medically known as polyuria, increased urination can develop when there are high levels of sugar in the blood. That's because the excess glucose ends up in the urine, according to the JDRF.⁴

The JDRF says that people with type 1 diabetes might urinate not only more frequently, but also in larger amounts.

Children who are potty-trained may start having nighttime accidents due to an increase in urine production, the American Diabetes Association (ADA) notes.⁵

Excessive Thirst

Increased thirst can be a sign of type 1 diabetes, especially among children and adolescents.³

The medical term for the symptom is polydipsia. People with type 1 diabetes might experience excessive thirst because their increased urination can cause dehydration, the JDRF reports.⁶

Increased Hunger

Experiencing an increase in hunger even though you are eating can be a sign of type 1 diabetes, per the ADA.⁵ Known medically as polyphagia, the symptom is possible in adults, but it is especially prevalent among children and adolescents.³

The fact that type 1 diabetes interrupts your body's ability to use glucose for energy might be what leads to this hunger, according to the JDRF.⁶

Unexpected Weight Loss

If you are eating the same amount of food—or more—than you usually do and begin losing weight, that can be a sign of the disease. The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) notes that unexplained weight loss can indicate type 1 diabetes.⁷

The JDRF says this symptom could be related to an increase in urination that the disease can cause: If your body isn't absorbing sugar like it should and is instead losing it in your urine, you may unexpectedly lose weight.⁶

Weakness and Fatigue

Weakness and fatigue are also associated with type 1 diabetes. With fatigue, you may find that getting enough sleep can't help your tiredness, according to MedlinePlus.⁸ Fatigue can limit your physical and mental functioning and worsen your quality of life, according to a 2018 editorial in Diabetes Therapy.⁹

A breakdown of muscle and fat that can be involved in type 1 diabetes might be what causes the weakness and fatigue, according to a 2021 article in the National Library of Medicine.¹⁰

Blurred Vision

Blurred vision can also occur with type 1 diabetes. High glucose can cause swelling or a rise in fluid levels in the eye tissues that help you focus, according to the NIDDK.¹¹

If the diabetes is diagnosed and treated, this symptom can go away once your glucose levels are brought back to normal levels with proper treatment.

Diabetic Ketoacidosis

For some people whose type 1 diabetes has yet to be diagnosed, the first sign of the disease can be a life-threatening condition known as diabetic ketoacidosis (DKA). DKA occurs when levels of blood sugar become extremely high and insulin levels are low, per the CDC

At first you may think you have a stomach bug. That's because, according to a 2019 study published in the journal Cureus, DKA can begin with vague symptoms like¹²:

  • nausea
  • vomiting
  • stomach pain

The development of DKA is usually slow. But it can develop faster—even within a few hours—if vomiting is involved, the ADA reports.¹³

According to the CDC, other symptoms of DKA include¹⁴:

  • Fast, deep breathing
  • Dry skin and mouth
  • Flushed face
  • Fruity-smelling breath
  • Headache
  • Muscle stiffness or aches
  • Being very tired

When to See a Health Care Provider

Type 1 diabetes, though commonly associated with children, can develop at any age. If you experience any symptoms of type 1 diabetes, it is best to talk to a health care provider so they can determine what diagnostic and treatment steps may be needed.

Getting medical attention is especially important if you experience any symptoms of DKA. Since the condition can be life-threatening, the NIDDK says you should go to a health care provider or nearest emergency room right away if you suspect DKA.⁷

Type 1 diabetes symptoms may not appear right away in adults. In fact, diabetes is often found during routine blood checks, according to the ADA, which is one reason why getting routine bloodwork is important.⁵


Type 1 diabetes is a chronic condition that requires treatment, such as taking insulin, to manage. It is important to know the symptoms of the disease so that you recognize when you might need to visit a health care provider.

Paying attention to changes in your thirst, hunger, and frequency of urination can help you spot the classic first signs of the disease. Unexplained weight loss, weakness, and fatigue, along with other symptoms, may also be signs of type 1 diabetes and should be discussed with a health care provider.

The symptoms can come on suddenly and, if not evaluated and managed, can cause serious complications. But according to the ADA, the risk of those diabetes-related complications can be lowered with early detection and treatment.⁵


  1. MedlinePlus. Type 1 Diabetes.
  2. Centers for Disease Control and Prevention. What Is Type 1 Diabetes?
  3. Atkinson MA, Eisenbarth GS, Michels AW. Type 1 diabetes. Lancet. 2014;383(9911):69-82. doi:10.1016/S0140-6736(13)60591-7.
  4. JDRF. Polyuria and Type 1 Diabetes.
  5. American Diabetes Association. Type 1 Diabetes – Symptoms.
  6. JDRF. Symptoms of Diabetes Type 1 in Adults.
  7. National Institute of Diabetes and Digestive and Kidney Diseases. Type 1 Diabetes.
  8. MedlinePlus. Fatigue.
  9. Kalra S, Sahay R. Diabetes Fatigue Syndrome. Diabetes Ther. 2018;9(4):1421-1429. doi:10.1007/s13300-018-0453-x.
  10. National Library of Medicine. Diabetes mellitus type 1.
  11. National Institute of Diabetes and Digestive and Kidney Diseases. Diabetic Eye Disease.
  12. Shahid W, Khan F, Makda A, Kumar V, Memon S, Rizwan A. Diabetic Ketoacidosis: Clinical Characteristics and Precipitating Factors. Cureus. 2020;12(10):e10792. Published 2020 Oct 4. doi:10.7759/cureus.10792.
  13. American Diabetes Association. Diabetes & DKA (Ketoacidosis).
  14. Centers for Disease Control and Prevention. Diabetic Ketoacidosis.
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