What Should You Do if You Notice Diabetes Symptoms?
Schedule a blood test with your doctor immediately if you are experiencing increased thirst, frequent urination, unexplained weight loss, or persistent fatigue. If you experience signs of diabetic ketoacidosis — vomiting, fruity-smelling breath, rapid breathing, or confusion — call 911 or go to the emergency room. Early diagnosis can prevent serious and potentially irreversible complications.
Do not wait to see if symptoms resolve on their own. Undiagnosed diabetes allows blood sugar to remain elevated, which progressively damages blood vessels, nerves, kidneys, and eyes. The CDC estimates that complications of undiagnosed diabetes cost the US healthcare system billions of dollars annually and cause preventable suffering. A simple blood test — A1C, fasting plasma glucose, or random glucose — can confirm or rule out diabetes quickly. If your fasting glucose is 126 mg/dL or higher or your A1C is 6.5 percent or higher, diabetes is confirmed. Results can often be available within hours to days.
While waiting for your appointment, monitor for worsening symptoms. Drink plenty of water to stay hydrated, as high blood sugar causes dehydration through excessive urination. Avoid sugary beverages and foods high in refined carbohydrates. If you have a family member with diabetes and access to a blood glucose meter, a finger-stick reading can provide immediate information — though this does not replace laboratory confirmation. The American Diabetes Association emphasizes that a new type 2 diabetes diagnosis is not a crisis but an opportunity: people diagnosed and treated early have the best long-term outcomes.
The CDC estimates that 8.7 million Americans have undiagnosed diabetes, representing roughly 23 percent of all diabetes cases
What Are the Classic Symptoms of Diabetes?
The classic diabetes symptoms — known as the three polys — are polyuria (excessive urination), polydipsia (excessive thirst), and polyphagia (excessive hunger). These result directly from elevated blood glucose levels and the body's inability to use glucose effectively for energy. Unexplained weight loss and persistent fatigue are also hallmark symptoms.
When blood glucose exceeds the kidney's reabsorption threshold (approximately 180 mg/dL), glucose spills into the urine through a process called glycosuria. Glucose in the urine draws water along with it through osmotic diuresis, causing polyuria — urination that is more frequent and higher in volume than normal. People may notice waking multiple times at night to urinate (nocturia) or urinating much more frequently during the day. The resulting fluid loss triggers intense thirst (polydipsia) as the body attempts to compensate for dehydration. Despite drinking large amounts of fluid, thirst may persist because the underlying cause — elevated blood glucose — remains.
Polyphagia (excessive hunger) and unexplained weight loss occur because cells cannot effectively access glucose for energy. In type 1 diabetes, the absence of insulin means glucose cannot enter cells at all. In type 2 diabetes, insulin resistance impairs glucose uptake. The body responds by increasing hunger signals, but consumed food continues to raise blood glucose rather than providing cellular energy. The body then turns to fat and muscle stores for energy, causing weight loss despite normal or increased food intake. Weight loss is typically more dramatic and rapid in type 1 diabetes, where insulin deficiency is absolute, and may be 10 to 20 pounds or more over weeks.
Blood glucose spills into urine when it exceeds the renal threshold of approximately 180 mg/dL, driving osmotic diuresis
- Polyuria: frequent, high-volume urination, especially at night
- Polydipsia: intense, persistent thirst despite drinking fluids
- Polyphagia: excessive hunger and increased food intake
- Unexplained weight loss, particularly rapid in type 1 diabetes
- Persistent fatigue, weakness, and low energy despite adequate rest
- Blurred or fluctuating vision
- Dry mouth and itchy skin
How Do Type 1 and Type 2 Diabetes Symptoms Differ?
Type 1 diabetes symptoms develop rapidly over days to weeks and are often severe, with DKA occurring in up to 30 percent of children at diagnosis. Type 2 diabetes symptoms develop gradually over months to years and are often subtle or absent. Approximately one-third of people with type 2 diabetes are undiagnosed because symptoms may go unnoticed.
Type 1 diabetes typically presents abruptly because the autoimmune destruction of beta cells reaches a critical threshold quickly. Children and adolescents may go from feeling well to seriously ill within a matter of days. Hallmark type 1 symptoms include rapid and significant weight loss, extreme fatigue, excessive thirst and urination, bedwetting in children who were previously dry at night, and irritability. Because type 1 diabetes involves absolute insulin deficiency, the body rapidly shifts to burning fat for fuel, producing ketones that accumulate in the blood and cause diabetic ketoacidosis. The CDC reports that DKA at diagnosis occurs in approximately 20 to 40 percent of children with new type 1 diabetes.
Type 2 diabetes typically develops insidiously over months to years. Early symptoms like mild fatigue, slightly increased thirst, or more frequent urination may be attributed to aging, stress, or other causes. Many people are diagnosed only when routine blood work reveals elevated glucose, or when they present with a complication such as a non-healing wound, recurrent infections, or vision changes. Some characteristic type 2 diabetes signs include acanthosis nigricans (darkened, velvety patches of skin on the neck, armpits, and groin), skin tags, recurrent yeast infections, erectile dysfunction in men, and slowly progressive peripheral neuropathy causing numbness or tingling in the feet.
What Are the Emergency Symptoms of Diabetic Ketoacidosis?
Diabetic ketoacidosis is a life-threatening complication primarily associated with type 1 diabetes, though it can occur in type 2. Emergency DKA symptoms include persistent nausea and vomiting, severe abdominal pain, fruity or acetone-smelling breath, rapid deep breathing, confusion, extreme drowsiness, and loss of consciousness. DKA requires immediate emergency treatment.
DKA develops when the body has insufficient insulin to use glucose and switches entirely to fat metabolism. The liver converts fatty acids into ketone bodies (acetoacetate, beta-hydroxybutyrate, and acetone) at a rate that overwhelms the body's buffering capacity, causing metabolic acidosis. Blood pH drops below 7.3, bicarbonate falls below 18 mEq/L, and serum ketones become significantly elevated. DKA typically develops over 24 hours or less and can progress to diabetic coma and death if untreated. The mortality rate for DKA is approximately 0.2 to 2 percent in developed countries with access to emergency care, but is much higher in resource-limited settings.
Common DKA triggers include missed insulin doses (the most frequent cause), insulin pump malfunction, new-onset type 1 diabetes, acute illness or infection (which increases insulin requirements due to stress hormones), emotional stress, certain medications including corticosteroids and SGLT2 inhibitors, and substance use. Euglycemic DKA, where DKA occurs with near-normal blood glucose levels, can occur with SGLT2 inhibitor use and is particularly dangerous because normal glucose readings may delay diagnosis. If you use an SGLT2 inhibitor and develop nausea, vomiting, or malaise, check for ketones even if your blood sugar appears normal.
DKA mortality is approximately 0.2 to 2 percent in developed countries with access to emergency care
What Are the Signs of Hypoglycemia?
Hypoglycemia (blood sugar below 70 mg/dL) causes symptoms that can be categorized as adrenergic (shakiness, sweating, rapid heartbeat, anxiety) and neuroglycopenic (confusion, difficulty speaking, blurred vision, loss of consciousness). Severe hypoglycemia is a medical emergency that can cause seizures, coma, and death if untreated.
Hypoglycemia is primarily a concern for people taking insulin or sulfonylureas, though it can occur in anyone with diabetes. As blood sugar drops, the body first releases counter-regulatory hormones including epinephrine (adrenaline), causing adrenergic symptoms: trembling, sweating, palpitations, anxiety, and hunger. These early warning signs (typically at glucose levels of 55 to 70 mg/dL) prompt the person to eat and correct the low blood sugar. The ADA recommends treating hypoglycemia with the rule of 15: consume 15 grams of fast-acting carbohydrate, wait 15 minutes, recheck blood sugar, and repeat if still below 70 mg/dL.
If blood sugar continues to fall below 54 mg/dL, neuroglycopenic symptoms develop as the brain is deprived of its primary fuel. These include confusion, difficulty concentrating, slurred speech, visual disturbances, incoordination, and behavioral changes that may be mistaken for intoxication. Severe hypoglycemia below 40 mg/dL can cause seizures, loss of consciousness, and if prolonged, permanent brain damage or death. People with long-standing diabetes may develop hypoglycemia unawareness, where the adrenergic warning symptoms are blunted, making dangerous lows more likely. The ADA reports that severe hypoglycemia affects approximately 30 to 40 percent of people with type 1 diabetes annually.
The ADA reports that severe hypoglycemia affects approximately 30 to 40 percent of people with type 1 diabetes annually
- Mild hypoglycemia (55-70 mg/dL): shakiness, sweating, hunger, rapid heartbeat, anxiety
- Moderate hypoglycemia (40-54 mg/dL): confusion, irritability, blurred vision, difficulty speaking, weakness
- Severe hypoglycemia (below 40 mg/dL): seizures, loss of consciousness, inability to self-treat
- Treatment: 15 grams fast-acting carbs (glucose tablets, 4 oz juice, regular soda), recheck in 15 minutes
- Severe hypoglycemia: administer glucagon injection or nasal glucagon (Baqsimi) and call 911
What Skin Changes Indicate Diabetes?
Several skin changes can signal diabetes or prediabetes. Acanthosis nigricans (darkened, velvety patches on the neck, armpits, and groin) indicates insulin resistance. Other diabetes-related skin changes include slow-healing wounds, frequent skin infections, dry itchy skin, diabetic dermopathy (shin spots), and necrobiosis lipoidica diabeticorum.
Acanthosis nigricans is one of the most recognizable external signs of insulin resistance and often appears before a diabetes diagnosis. It presents as dark, thick, velvety patches of skin, most commonly on the back and sides of the neck, armpits, groin folds, and under the breasts. The excess circulating insulin stimulates keratinocyte and fibroblast growth in the skin. Acanthosis nigricans is particularly common in children and adolescents with obesity and insulin resistance, and its presence should prompt diabetes screening. While not harmful itself, it serves as a visible marker of the metabolic dysfunction underlying type 2 diabetes.
Other diabetes-related skin manifestations include diabetic dermopathy (small, light brown, oval or circular patches on the shins), necrobiosis lipoidica diabeticorum (shiny, reddish-brown patches that may ulcerate, typically on the lower legs), digital sclerosis (tight, thick, waxy skin on the fingers and toes), and eruptive xanthomas (firm, yellow, pea-sized bumps indicating very high triglycerides). Bacterial and fungal skin infections are also more common in people with diabetes because elevated blood sugar impairs immune function and creates a favorable environment for microbial growth. Recurring boils, styes, nail infections, and yeast infections may be the presenting complaint that leads to a diabetes diagnosis.
What Symptoms Indicate Diabetes Complications?
Symptoms of diabetes complications include numbness, tingling, or burning pain in the feet (neuropathy), vision changes including floaters and blurriness (retinopathy), swelling in the legs and foamy urine (kidney disease), chest pain and shortness of breath (cardiovascular disease), and non-healing foot ulcers that may indicate peripheral arterial disease.
Diabetic peripheral neuropathy is the most common complication, affecting up to 50 percent of people with diabetes over time. Symptoms typically begin in the toes and feet and progress upward in a stocking-glove distribution. Early symptoms include tingling, pins and needles, numbness, and heightened sensitivity to touch. As neuropathy advances, patients may experience burning pain, electric shock sensations, or paradoxically, complete loss of sensation that makes foot injuries go unnoticed. Loss of protective sensation is the primary risk factor for diabetic foot ulcers and non-traumatic lower limb amputations. The NIDDK recommends that all people with diabetes perform daily foot inspections.
Diabetic retinopathy develops silently and may cause no symptoms until significant damage has occurred. When symptoms appear, they include floaters (dark spots or strings floating in vision), blurred or fluctuating vision, dark or empty areas in the visual field, and difficulty with color perception. Diabetic kidney disease (nephropathy) may cause no symptoms in early stages and is detected through annual urine albumin testing. Advanced nephropathy can cause leg swelling (edema), fatigue, loss of appetite, and foamy urine. Cardiovascular symptoms including chest pain, shortness of breath, and exertional fatigue should be evaluated immediately, as people with diabetes have a two to four fold increased risk of heart disease.
Diabetic peripheral neuropathy affects up to 50 percent of people with diabetes and is the leading cause of non-traumatic lower limb amputations
When Should You Get Screened for Diabetes?
The ADA recommends diabetes screening for all adults beginning at age 35, regardless of risk factors, and earlier for those who are overweight with one or more risk factors. Children and adolescents who are overweight with risk factors should be screened starting at age 10 or at puberty onset. Screening involves a simple blood test: A1C, fasting glucose, or oral glucose tolerance test.
Screening is critical because type 2 diabetes and prediabetes can exist for years without symptoms while silently causing damage. The ADA screening recommendations aim to identify diabetes and prediabetes early when interventions are most effective. Additional populations that should be screened regardless of age include all women with a history of gestational diabetes (every 1 to 3 years for life), people with HIV, patients starting therapy with medications associated with diabetes risk (glucocorticoids, antipsychotics, statins), and people with clinical conditions associated with insulin resistance such as severe obesity, acanthosis nigricans, or polycystic ovary syndrome.
For children and adolescents, the ADA recommends screening for type 2 diabetes beginning at age 10 or at onset of puberty (whichever occurs earlier) in youth who are overweight (BMI above the 85th percentile) or obese with one or more risk factors. Risk factors include maternal gestational diabetes during the child's gestation, family history of type 2 diabetes in a first- or second-degree relative, high-risk ethnicity, and signs of insulin resistance (acanthosis nigricans, hypertension, dyslipidemia, PCOS). If screening results are normal, repeat testing every 3 years is recommended, or more frequently if BMI is increasing or risk factors change.
The ADA recommends universal diabetes screening for all adults beginning at age 35, with earlier screening for those with risk factors
