10 Unusual Symptoms of Diabetes

The most common symptoms of diabetes include increased thirst, frequent urination, and excessive fatigue. However, some less common symptoms (blurred vision, excessive hunger, mood swings, and more) may be confused with other conditions.

People with diabetes need to look out for these less common symptoms, even if they already have a diagnosis and treatment plan. These symptoms could suggest that their blood sugar is not under control. Additionally, some symptoms develop so gradually that they can be missed.

This article explores 10 less common symptoms of diabetes.

blood sugar testing

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When to Contact Your Healthcare Provider

If you have symptoms of diabetes, it's important to contact your healthcare provider. Long-term uncontrolled high blood sugar can lead to complications that can be life-threatening. Hyperglycemic hyperosmolar nonketotic syndrome (HHNS) and diabetic ketoacidosis (DKA) are potentially fatal conditions in individuals with undiagnosed or uncontrolled high blood sugar.

Excessive Hunger

The body uses sugar from the foods we eat to make fuel for cells. Insulin is a hormone that takes sugar out of the blood so that cells can use it for energy. When insulin is inadequate, the sugar stays in the blood instead of being used for energy. As a result, individuals with uncontrolled or undiagnosed high blood sugar may feel increasingly hungry (polyphagia) as the body attempts to signal for more fuel for cells.

Sudden Weight Loss

Sudden weight loss is more common in children with undiagnosed type 1 diabetes, primarily if it occurs with other symptoms like bedwetting, increased hunger, and increased thirst.

Weight loss is less common in patients with type 2 diabetes since this condition usually develops more gradually and is often linked to people with obesity or who are overweight. However, sudden weight loss could suggest problems with blood sugar. About 10% of people living with diabetes are normal or underweight.

Tingling in Hands and Feet

Chronic high blood sugar can damage the small blood vessels in the hands and feet, leading to peripheral neuropathy. The condition affects more than half of all people with type 1 and type 2 diabetes.

Diabetic peripheral neuropathy usually starts as numbness or tingling in the hands or feet. If left untreated, it may progress to muscle weakness, burning or stabbing pain, and loss of sensation. It is usually worse at night. Reduced sensation may increase injury risk.

Mood Swings

High and low blood sugar can cause mood swings or irritability. When the brain doesn't get the glucose it needs, it can cause difficulty in making decisions, sadness, and anxiety.

Long-term uncontrolled blood sugar can cause damage to the nerves and blood vessels in the brain, ultimately affecting memory and learning; weight gain; and hormone changes, and it even increases the risk of developing Alzheimer's disease.

Slow-Healing Wounds

High blood sugar can affect the immune system and circulation, making it more difficult for wounds to heal. Diabetes can damage blood vessels, which makes it harder for blood to reach organs and tissues. High blood sugar can also impact the immune system, so fewer immune-fighting cells can respond to cuts or infections.

Some people with diabetes have reduced sensation in their feet and legs, making them more prone to injury. Some may not feel a cut or injury immediately, leading to infection or further injury if the wound goes untreated.

Urinary Tract Infections

Urinary tract infections (UTIs) are more common in uncontrolled high blood sugar patients for three main reasons:

  • High blood sugar levels in urine make it more likely that bacteria will grow.
  • High blood sugar levels in the blood impact immune function.
  • High blood sugar levels lead to damage to the nerves in and around the bladder, so urine may remain in the bladder longer, allowing bacteria to grow and spread more easily.

Additionally, UTIs are more difficult to treat and may lead to more serious complications in patients with high blood sugar.

Yeast Infections

Yeast and other fungal infections are more common in people with diabetes. This is because sugar helps yeast grow, and people with high blood sugar usually have higher sugar levels in their sweat, saliva, and urine.

Yeast thrives in areas that are dark and moist, which means that people with diabetes are more likely to develop problems with yeast infections in their mouth, genitals, between their toes, or under their breasts.

Fruity-Smelling Breath

Fruity-smelling breath is a dangerous symptom in patients with type 1 diabetes.

When there is not enough insulin, the body cannot convert sugar in the blood into glucose, which the body uses for fuel. Without glucose, the body starts using fat as fuel in a process known as ketosis. As ketones are released into the blood, they may begin poisoning the person.

This condition is known as diabetic ketoacidosis, which can be fatal if left untreated. Fruity-smelling breath is a reason to call your healthcare provider immediately, especially if it occurs with other symptoms like excessive thirst, frequent urination, and confusion.

Dark Skin Around the Neck

Acanthosis nigricans is a skin condition involving dark, thickened skin patches. It usually develops in skin fold areas, like under the arms, around the neck, and in the groin area. Research suggests that acanthosis nigricans is associated with a higher risk of developing type 2 diabetes.

Blurry Vision

High blood sugar can damage small blood vessels in nerves in the eyes, resulting in blurred vision. Without treatment, vision changes related to uncontrolled blood sugar can even lead to blindness.

Diabetes can affect different structures in the eyes. Sometimes, the change may affect only one eye. Other changes to look out for include:

  • Wavy lines at the center of the field of vision
  • Washed out or faded colors
  • Floaters (spots or strings floating in your vision)
  • Dark or empty spaces in your vision
  • Eye pain or pressure
  • Headaches
  • Seeing rainbow-colored halos around lights
  • Tunnel vision
  • Blind spots


Early symptoms of diabetes can be missed or mistaken for other conditions. Uncommon symptoms include mood swings, increased fungal or urinary tract infections, and blurred vision, among others. Symptoms like tingling or numbness in the feet, slow wound healing, or fruity breath may also suggest that patients diagnosed with diabetes may not have their blood sugar under control.

A Word From Verywell

Early recognition of symptoms and swift intervention can significantly improve long-term outcomes for people in the early stages of diabetes. If you experience new symptoms like blurry vision, dark skin around the neck, or unexplained mood swings, it's worth speaking with your healthcare provider. While diabetes and prediabetes can be challenging to manage, some resources can help.

Frequently Asked Questions

  • Can diabetes be mistaken for other diseases?

    Many symptoms of diabetes may occur with other conditions as well. For example, liver disease can also lead to fruity-smelling breath. Dark skin around the neck may also be related to obesity or polycystic ovarian syndrome (PCOS). Any new or unusual symptom is worth speaking to your healthcare provider about.

  • Why does diabetes make you feel unwell?

    Diabetes can cause changes throughout the body down to the smallest blood vessels and nerve endings. In the short-term, low blood sugar may make you feel dizzy, shaky, irritable, or generally unwell. Long-term high blood sugar can also lead to more significant problems, like heart disease, kidney failure, or vision loss.

16 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Elizabeth Morrill, RN
Elizabeth Morrill is a former ER nurse and current nurse writer specializing in health content for businesses, patients, and healthcare providers. Her career has spanned the globe, from Bosnia-Herzegovina to Colombia to Guatemala. You can find her online at www.emfreelancing.com.