What Are the Symptoms of Uncontrolled Diabetes?

Uncontrolled diabetes is defined as having sustained high blood sugar levels (hyperglycemia) or frequent low blood sugars (hypoglycemia). People with uncontrolled diabetes have a greater risk of diabetic complications.

Diabetes may be uncontrolled because it is undiagnosed, the current treatment is ineffective, or there's a lack of compliance with treatment. Classic symptoms of uncontrolled blood sugar include excessive thirst, fatigue, and blurred vision. But there are many less obvious signs as well.

This article discusses the symptoms of uncontrolled diabetes. It explains the common and uncommon signs of high blood sugar and when to talk to your healthcare provider.

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How Uncontrolled Diabetes Affects the Body

Uncontrolled diabetes is defined as having sustained blood glucose (sugar) levels are 180 milliliters per deciliter (ml/dL) or higher. When diabetes is uncontrolled, persistently high blood sugar levels can damage nerves, blood vessels, and vital organs.

When a person has diabetes, insulin produced by the pancreas is not able to move glucose into cells for energy as it is supposed to. As the blood sugar starts to accumulate, it can become toxic to organs and tissues, silently damaging them over time.

The complications of diabetes are broadly divided into two categories:

  • Microvascular: These are complications caused by damage to small blood vessels, including those servicing the eyes, kidneys, and nervous symptoms. The triad of microvascular complications is referred to individually as diabetic retinopathy (involving eyes), diabetic nephropathy (involving kidneys), and diabetic neuropathy (involving nerves).
  • Macrovascular: These are complications caused by damage to large blood vessels. Macrovascular complications of diabetes include cardiovascular disease, stroke, and peripheral artery disease (PAD).

Other complications include dental disease, reduced resistance to infections, and pregnancy and birth complications caused by gestational diabetes or pre-existing diabetes in pregnancy.

How Long Can You Live with Uncontrolled Diabetes?

Uncontrolled type 1 diabetes can quickly escalate to a life-threatening complication called diabetic ketoacidosis (DKA). DKA can come on quickly—in as little as 24 hours—or take several weeks of uncontrolled high blood sugar to set in.

While people with uncontrolled type 2 diabetes can also develop DKA, it is less common. Uncontrolled type 2 diabetes can shorten your lifespan in other ways. Sustained high blood sugar also increases your risk of complications that may be disabling.

On average, the life expectancy of people with type 2 diabetes is six years shorter than nondiabetics. However, research shows improving blood sugar control can add 3.8 years back.

Hyperglycemia (High Blood Glucose)

Hyperglycemia (high blood sugar) is a potentially serious condition that occurs when the body does not produce enough insulin or insulin is not properly utilized.

Hyperglycemia is diagnosed when blood glucose levels are higher than 100 mg/dL while fasting, higher than 180 mg/dL one to two hours after the start of a meal, or when your blood glucose level is higher than 200 mg/dL.

In the early stages of diabetes, there may be few, if any, symptoms. If there are, they typically include:

  • Blurry vision
  • Excessive thirst
  • Increased hunger
  • Fatigue
  • Frequent urination

In more severe hyperglycemic events,  a person may experience:

  • Loss of consciousness
  • Nausea and vomiting
  • Rapid breathing
  • Rapid heartbeat
hyperglycemia symptoms


Foot Infections

Uncontrolled high blood sugar can weaken the body's immune system and make it harder to fight infections. It also makes it easier for bacteria to penetrate and thrive in damaged tissues and organs.

One such example of this is diabetic foot syndrome. This occurs when impaired blood flow to the foot not only increases the risk of infection but reduces the availability of immune cells to fight the infection. The reduced blood flow also prevents the proper formation of scabs and the remodeling of new tissues.

Slow wound healing is the hallmark of diabetic foot syndrome. With uncontrolled diabetes, sores can fester and cause tissue death, leading to the onset of gangrene.

Symptoms of diabetic foot syndrome include:

  • Burning or pins-and-needles sensations
  • Dry skin
  • Foot ulcers
  • Leg or foot wounds that are slow to heal
  • Pain or cramping in the legs
  • Poor nail growth
  • Skin discoloration

Foot Ulcers

If left untreated, diabetic foot ulcers can lead to leg amputation, sepsis (a potentially deadly inflammatory reaction to the spread of infection), and even death.

Frequent Urination

If you wake up multiple times during the night to use the bathroom or urinate more frequently and in larger amounts, you may be experiencing polyuria.

Polyuria is the medical term for frequent urination. It is a symptom of diabetes that can lead to extreme dehydration and kidney injury if your blood sugar is not kept in check.

Polyuria with diabetes is the direct result of high blood sugar. Normally, when your kidneys create urine, they reabsorb all the sugar and direct it back to the bloodstream.

This does not happen with uncontrolled diabetes. Instead, the excess glucose ends up in the urine, which acts as an osmole (meaning a substance that alters the movement of fluids). The osmotic effect draws more fluid into the kidneys, leading to increased urination.

Uncontrolled diabetes is just one cause of polyuria. Frequent urination is also a side effect of diuretic medications and lithium, and can be caused from drinking alcohol or caffeinated beverages and early pregnancy. 

Frequent Thirst

Polydipsia (meaning frequent or excessive thirst) commonly accompanies polyuria in people with uncontrolled diabetes. This is due to the dehydration caused by the rapid and persistent loss of body fluid through urination.

Extreme dehydration can also make your blood sugar rise quickly due to the decreased fluid volume in the body. Polydipsia may also be accompanied by nausea, headaches, dizziness, bad breath, dark-colored urine, or fainting.

Drinking more water may help in the short term, but it doesn't solve the underlying problem. To curb your thirst, you need to get your blood sugar under control. 

Extreme Fatigue

Fatigue is common in people with uncontrolled diabetes. Although there is little understanding as to why this occurs, several factors are known to contribute to lethargy in people with diabetes, including:

  • Being overweight or obese
  • Depression
  • Frequent hyperglycemic attacks
  • Sleep problems
  • Stress

Extreme fatigue plays a significant role in the quality of life and should not be overlooked as a symptom of diabetes.

Diabetic Ketoacidosis

Diabetic ketoacidosis (DKA) is a potentially life-threatening complication that can lead to coma or death if not treated immediately.

DKA occurs when your body doesn't have enough insulin to transport glucose into cells for energy. As result, the liver will start to break down fat for fuel, triggering the excess production of a byproduct called ketones. When too many ketones are produced too quickly, they can build up in the blood to dangerous levels.

This complication most frequently affects people with type 1 diabetes but, in rare cases, can affect people with type 2 diabetes. DKA symptoms tend to develop rapidly, often within 24 hours, causing symptoms such as:

  • Dried skin or mouth
  • Flushed skin
  • Frequent urination
  • Fruity breath odor
  • Increased thirst
  • Loss of concentration or confusion
  • Muscle aches or stiffness
  • Nausea or vomiting
  • Stomach pain 

The two most common causes of DKA are illness and poor insulin control.

Constant Hunger

Polyphagia is a term used to describe excessive hunger or increased appetite. It is one of the three main signs of diabetes, alongside increased thirst and frequent urination.

When diabetes is uncontrolled, it prevents glucose from entering cells for conversion into energy. The lack of energy sends signals to the brain, suggesting that more food is needed to bring energy levels back up.

Eating a meal may help relieve diabetic polyphagia in the short term, but it will not treat the underlying cause. It may worsen the problem by adding to already high blood sugar levels.

Blurry Vision

Blurry vision is sometimes one of the earliest signs of diabetes. It can occur when your blood sugar levels are too high, too low, or rapidly fluctuating.

A sudden spike in blood sugar can cause fluids to build up within the eye, causing short-term changes to the shape of the lens. After a severe hypoglycemic attack, it can sometimes take up to six weeks for the blurriness and visual distortions to clear.

By contrast, when your blood sugar levels are too low—known as hypoglycemia—your vision can get blurry due to the way that hypoglycemia affects the brain.

Uncontrolled diabetes can also damage the small vessels of the eye, causing them to bleed and leak fluid into the retina (the layer of tissue to the back of the eye). Over time, the persistent swelling can damage the retina, leading to a condition known as diabetic retinopathy, in which blurred vision and vision loss are common.

Diabetes is today the leading cause of blindness in people ages 20 to 74 in the United States, according to the National Eye Institute.

Weight Loss

If diabetes is uncontrolled and your blood sugar levels are persistently high, it can cause the body to break down fat and muscle for energy, leading to a notable loss in weight and muscle mass.

Muscle is heavier than fat, so weight loss is common in people with uncontrolled diabetes. Excessive urination also means that you are losing excessive amounts of water, which can contribute to weight fluctuations. 

Hearing Problems

Hearing loss is more common in people with uncontrolled diabetes, although the reasons for this are not clear. It can even affect people with prediabetes (in which blood sugar is higher than normal but not high enough to be considered diabetes).

According to the American Diabetes Association, hearing loss is twice as likely in people with diabetes than in those without. Moreover, of the 88 million adults in the United States who have prediabetes, the rate of hearing loss is 30% higher than in those with normal blood glucose levels.

Some researchers believe that high blood sugar causes damage to the small blood vessels in the inner ear. Others contend that it increases pressure in the fluid-filled cochlea, which acts as the microphone of the ear.

Circulation Problems

Elevated glucose levels over many years can contribute to the build-up of fatty deposits in the blood vessels called plaque. When it affects blood vessels outside of the heart and brain, it can lead to a condition known as peripheral artery disease (PAD).

The symptoms of PAD are wide-ranging and can involve multiple organ systems, including the skin, lungs, joints, connective tissues, digestive tract,

Symptoms of PAD in people with diabetes include:

  • Fatigue
  • Brittle toenails
  • Chest pain when exercising
  • Hair loss on the legs and feet
  • Numbness and tingling in the hands and feet
  • Swelling in the feet, ankles, and legs
  • Digestive problems
  • Joint and muscle cramping
  • Skin color changes
  • Leg or foot ulcers
  • Varicose veins
  • Memory loss
  • Difficulty concentrating

The risk of peripheral artery disease (PAD) is high in people with uncontrolled diabetes. PAD not only occurs earlier than in people without diabetes but is more likely to be severe.

Skin Conditions

Diabetes can affect the skin in different ways. In people with long-standing diabetes, it can sometimes cause irreversible skin changes. Other skin problems only arise when blood sugar levels are high and will clear once the levels are normalized.

Acanthosis Nigricans

Acanthosis nigricans (AN) is a skin disorder characterized by velvety, raised, darkly pigmented skin lesions found mainly in body folds (such as under the armpit or in the groin). People who have obesity or diabetes are most likely to experience AN.

AN is most commonly linked to insulin resistance. This is when cells in your muscles, fat, and liver don't respond well to insulin and cannot utilize glucose from the blood for energy.

Although AN is relatively benign, it can be a signal that you have diabetes or that your diabetes is not being adequately controlled.

Necrobiosis Lipoidica Diabeticorum

Necrobiosis lipoidica diabeticorum (NLD) is caused by changes in the blood vessels due to uncontrolled diabetes. NLD causes large spots, usually on the lower legs, that start as reddish, raised patches of skin. Over time, these morph into shiny scars with a violet border.

The cause of NLD is unknown but is more common in females than males. NLD can sometimes be itchy or painful but usually doesn't require treatment other than to normalize blood sugar levels.

Bullous Diabeticorum

On rare occasions, diabetes can cause blisters to form on the hands, feet, legs, and forearms. The condition, called bullous diabeticorum, is seen almost exclusively in people with long-standing diabetes and poor glucose control.

The blisters look similar to burn blisters and are often accompanied by tingling or pin-and-needles sensations. Despite their large size and unsightly appearance, the blisters usually don't cause outright pain. The blisters tend to resolve within three weeks if blood sugar levels are brought under control.

Eruptive Xanthomatosis

Uncontrolled diabetes can lead to eruptive xanthomatosis (EX), a skin condition that causes the appearance of firm, yellow, pea-like enlargements surrounded by a red halo. The condition can be itchy and most often develops on the backs of hands, feet, arms, legs, and buttocks.

Males are more likely to experience EX than females. As with bullous diabeticorum, these bumps will disappear once diabetes is brought under control.

Digital Sclerosis

Digital sclerosis is a long-term complication of diabetes that typically occurs when blood sugar is not effectively managed. Digital sclerosis is caused by reduced blood flow to the limbs and causes the stiffening of tissues around the joints of the toes, fingers, and hands.

Digital sclerosis will cause the skin will become tight, thick, and waxy, while the underlying joints will be harder to flex or extend. The only treatment for digital sclerosis is to bring blood sugar levels back under control.

Disseminated Granuloma Annulare

Disseminated granuloma annulare (DGA) is a self-limited, benign condition that affects the top two layers of skin called the dermis and subcutaneous tissues. DGA is associated with poor glucose control but may also be the first sign of diabetes in some people.

DGA is most commonly seen in adults with diabetes, causing raised patches of pink, mauve, or flesh-colored skin with well-defined borders. The fingers, hands, and feet are the areas most often affected.

DGA tends to clear on its own and generally improves with well-controlled diabetes.

Long-Term Effects of Uncontrolled Diabetes

Over time, uncontrolled high blood sugar leads to long-term complications. Some complications, like blindness and kidney failure, are permanent. Other complications, like peripheral neuropathy, may be reversible if caught early.

Uncontrolled diabetes can lead to a decreased quality of life due to complications. It can also lead to heart disease, including fatal heart attacks and strokes.

Managing your blood sugar can help to prevent complications. If you are having difficulty keeping your blood sugar levels in range, talk to your healthcare provider about changing your treatment plan.

When to See Your Healthcare Provider

If you are not diagnosed with diabetes, talk to your healthcare provider about getting tested for diabetes if you experience the following symptoms:

  • Blurry vision
  • Constant hunger
  • Excessive thirst
  • Extreme fatigue
  • Frequent urination
  • Unintended weight loss

People with diagnosed diabetes should see their healthcare provider several times a year. If it has been six months or longer since your last A1c or you are having difficulty managing your blood sugar, make an appointment for a diabetes check-up.

Diabetes management looks different for everyone. Some people are able to control their blood sugar with diet and exercise alone. Others need insulin or other blood-sugar-lowering medications. If your current treatment isn't working to control your blood sugar, your healthcare provider can help.


Uncontrolled diabetes can affect many organs of the body due to the damaging effects of high blood sugar. Many of the symptoms will clear once the blood sugar is brought under control. Others may cause permanent, irreversible damage.

Symptoms of uncontrolled diabetes include extreme fatigue, frequent urination, excessive thirst or hunger, unintended weight loss, and blurred vision.

Severe cases of uncontrolled diabetes can also lead to a potentially life-threatening build-up of acids in the blood called diabetic ketoacidosis,

A Word From Verywell

You can avoid complications of diabetes—and live healthier and longer—by managing your blood sugar with medications, routine exercise, and a low-carbohydrate diet. Weight loss can also help reverse insulin resistance seen in people with type 2 diabetes and prediabetes.

Setting realistic goals can help you stay on track. By developing a healthy lifestyle routine you can stick with, you will be far more likely to control your diabetes while reducing the risk of other chronic diseases, like high blood pressure, heart disease, and kidney disease.

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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 Shamard Charles, MD, MPH
Shamard Charles, MD, MPH is a public health physician and journalist. He has held positions with major news networks like NBC reporting on health policy, public health initiatives, diversity in medicine, and new developments in health care research and medical treatments.