Type 2 Diabetes Symptoms Uncontrolled Diabetes Symptoms By Shamard Charles, MD, MPH Shamard Charles, MD, MPH LinkedIn Twitter Shamard Charles, MD, is a physician-journalist and public health doctor who advances health policy through health communication and health promotion. Learn about our editorial process Updated on October 22, 2022 Medically reviewed by Do-Eun Lee, MD Medically reviewed by Do-Eun Lee, MD LinkedIn Do-Eun Lee, MD, has been practicing medicine for more than 20 years, and specializes in diabetes, thyroid issues and general endocrinology. She currently has a private practice in Lafayette, CA. Learn about our Medical Expert Board Print Table of Contents View All Table of Contents Untreated Diabetes Symptoms High Blood Sugar and Your Body Hyperglycemia Foot Infections Frequent Urination Frequent Thirst Extreme Fatigue Diabetic Ketoacidosis Constant Hunger Blurry Vision Weight Loss Hearing Problems Circulation Problems Skin Conditions If you have diabetes and your blood sugar is uncontrolled, you may experience the classic symptoms of high blood sugar, including excessive thirst and blurred vision. But there may be other symptoms you may not recognize as being diabetes-related, such as foot sores that are slow to heal or a "mental fog" that interferes with your concentration. Controlling your blood sugar with diet, exercise, and medications can not only help you avoid sugar spikes but also reduce your risk of potentially life-threatening complications like diabetic ketoacidosis, heart attack, or stroke. This article explains how diabetes damages your organs and outlines some short- and long-term symptoms that can arise from uncontrolled blood sugar. Getty Images Untreated Diabetes Symptoms If left untreated, diabetes signs and symptoms can include: High blood sugarFoot infectionsFrequent urinationFrequent thirstExtreme fatigueDiabetic ketoacidosisConstant hungerBlurry visionUnintended weight lossHearing problemsCirculation problemsSkin conditions High Blood Sugar and Your Body Uncontrolled diabetes is diagnosed when your 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. Types of Diabetes Mellitus 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 visionExcessive thirstIncreased hungerFatigueFrequent urination In more severe hyperglycemic events, a person may experience: Loss of consciousness Nausea and vomiting Rapid breathing Rapid heartbeat Symptoms of Hyperglycemia Verywell 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 sensationsDry skinFoot ulcersLeg or foot wounds that are slow to healPain or cramping in the legsPoor nail growthSkin 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. What Is Diabetic Neuropathy? Frequent Urination If you are waking up multiple times during the night to use the bathroom or urinating 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 in 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. 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 volumes 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 people with diabetes, including: Being overweight or obeseDepressionFrequent hyperglycemic attacksSleep problemsStress Extreme fatigue plays a significant role in the quality of life and should not be overlooked as a symptom of diabetes. High Blood Sugar in People Without 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, your 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. Causes and Symptoms of Nocturnal Hyperglycemia 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. How to Screen for Diabetic Retinopathy 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. Could Rapid Weight Loss Mean Diabetes? 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. Can Diabetes Make You Go Deaf? 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: FatigueBrittle toenailsChest pain when exercisingHair loss on the legs and feetNumbness and tingling in the hands and feetSwelling in the feet, ankles, and legsDigestive problemsJoint and muscle crampingSkin color changesLeg or foot ulcersVaricose veinsMemory lossDifficulty 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 a shiny scar 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. The Effects of Diabetes on Skin Summary 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. Among the signs and symptoms of uncontrolled diabetes are: Extreme fatigueFrequent urinationExcessive thirst or hungerUnintended weight lossSkin changesBlurred visionSlow-healing foot infectionsHearing problems 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. 19 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. Papatheodorou K, Banach M, Bekiari E, Rizzo M, Edmonds M. Complications of diabetes 2017. J Diabetes Res. 2018 Mar 11;2018:3086167. doi:10.1155/2018/3086167 Tuttolomondo A., Maida C., Pinto A. Diabetic foot syndrome as a possible cardiovascular marker in diabetic patients. J Diabetes Res. 2015;2015:12. doi:10.1155/2015/268390.268390 American Diabetes Association. 6. Glycemic targets: Standards of medical care in diabetes—2022. 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Centers for Disease Control and Prevention. Diabetes symptoms. Sayin N, Kara N, Pekel G. Ocular complications of diabetes mellitus. World J Diabetes. 2015;6(1):92-108. doi:10.4239/wjd.v6.i1.92 National Eye Institute. People with diabetes can prevent vision loss. American Diabetes Association. Diabetes and hearing loss. American Heart Association. Peripheral artery disease and diabetes. National Organization of Rare Disorders. Ancanthosis nigricans. American Osteopathic College of Dermatology. Necrobiosis lipoidica diabeticorum. Agrawal P, Pursnani N, Jose R, Farooqui M. Granuloma annulare: A rare dermatological manifestation of diabetes mellitus. J Family Med Prim Care. 2019;8(10):3419-3421. doi:10.4103/jfmpc.jfmpc_616_19 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. See Our Editorial Process Meet Our Medical Expert Board Share Feedback Was this page helpful? Thanks for your feedback! What is your feedback? Other Helpful Report an Error Submit