Glucose 382 mg/dL
= 21.2 mmol/L in SI units
Contact your doctor promptly to discuss this result.
- Critically low (panic value)
- Severely low (serious hypoglycemia)
- Low (mild hypoglycemia)
- Normal
- Borderline high (prediabetes range)
- High (diabetes range)
- Very high
- Severely high
At a glance
- Your band
- Severely high · 3–4 mg/dL
- Distance from typical range
- 282 mg/dL above 100
- SI units
- 382 mg/dL = 21.2 mmol/L
What 382 mg/dL means
A glucose of 382 mg/dL is severely elevated — far above the diabetes diagnostic threshold and at or beyond the level many labs flag as a critical value.
Glucose this high causes real fluid loss through the urine and, if it continues, can progress to diabetic ketoacidosis (DKA) or, especially in older adults, a hyperosmolar state — both medical emergencies. Whether this needs the ER right now depends on how you feel: a person who feels reasonably well still needs same-day medical contact, while anyone with vomiting, labored breathing, or confusion needs emergency care immediately. Either way, this number should not wait for a routine appointment. If your reported result is 400 mg/dL or higher — the top of this guide's scale, and a level many US labs phone directly to the ordering clinician — treat it as a critical value: contact your care team or go to urgent care or the ER today even if you feel well. Sustained readings at this level can progress to diabetic ketoacidosis or a hyperosmolar emergency, and higher numbers are more dangerous than this scale can show.
Most US labs list a fasting glucose reference range of about 70–99 mg/dL, following American Diabetes Association criteria; glucose ranges are not split by sex. Low readings are tiered using the ADA's hypoglycemia levels — 54–69 mg/dL is level 1 (an alert value) and below 54 mg/dL is level 2 (clinically serious) — and most US labs additionally treat values below about 40 mg/dL as a critical (panic) value, though the exact callback threshold varies slightly by lab. There is no recognized 'borderline low' category for glucose; 70 mg/dL is the accepted lower cutoff.
Common causes
- Uncontrolled or undiagnosed diabetes
- Stopped or missed insulin
- Serious infection (urinary, pneumonia, skin) in someone with diabetes
- New-onset type 1 diabetes, which can escalate quickly
- High-dose corticosteroids
- Heart attack, stroke, or other major physical stress
- Insulin pump failure or spoiled insulin
Symptoms that can go with it
- Extreme thirst
- Urinating very frequently, including overnight
- Marked fatigue or weakness
- Blurred vision
- Nausea or vomiting
- Deep, rapid breathing or fruity-smelling breath (warning sign of DKA)
- Confusion or unusual drowsiness (warning sign — treat as an emergency)
Sensible next steps
- If your reported result is 400 mg/dL or higher — the top of this guide's scale — treat it as a critical value: contact your care team or go to urgent care or the ER today even if you feel well; sustained readings at this level can progress to diabetic ketoacidosis or a hyperosmolar emergency, and higher numbers are more dangerous than this scale can show
- Seek medical care today: call your doctor or diabetes care team now, or go to urgent care if you can't reach them — and go straight to the emergency department if you have vomiting, stomach pain, deep or rapid breathing, fruity breath, confusion, or extreme drowsiness
- If you use insulin, take doses as prescribed and check ketones now if you have test strips; ketones plus a reading this high means emergency care
- Sip water steadily to counter fluid loss unless a doctor has restricted your fluids
- Do not exercise while glucose is this high, especially if ketones are present
- Once stable, work with your clinician on why this happened — missed medication, infection, or a treatment plan that needs strengthening
Frequently asked questions
Is 382 mg/dL a normal glucose level?
No — 382 mg/dL is severely elevated and needs same-day medical attention. Go to the ER if you have vomiting, deep breathing, confusion, or extreme drowsiness.
Does a fasting glucose of 382 mean I have diabetes?
At 382 mg/dL, diabetes is almost certain and the immediate priority is getting the level down safely. Seek medical care today rather than waiting on confirmatory testing.
What blood sugar level is dangerous?
On the low side, glucose below 54 mg/dL is clinically serious and below about 40 mg/dL is a lab panic value — severe lows can cause seizures or loss of consciousness. On the high side, sustained readings above 300 mg/dL risk diabetic ketoacidosis or a hyperosmolar state, and many labs flag values around 400 mg/dL and above as critical. Symptoms matter as much as the number: confusion, vomiting, or labored breathing alongside an extreme reading means emergency care.
Do I need to fast before a glucose test, and does coffee affect it?
A fasting glucose test requires 8–12 hours with nothing but water — food, juice, soda, and even coffee with cream or sugar can raise the result. Black coffee has little direct sugar but can still nudge glucose up slightly in some people, so most labs ask you to skip it. If you didn't fast properly, tell your clinician; the fix is usually just repeating the test, not worrying about the number.
How can I lower my blood sugar?
A level this high cannot be fixed with diet and exercise — it needs medical treatment today, usually medication or insulin adjustment. Do not exercise until it comes down, especially if ketones are present, and seek same-day care; lifestyle changes come later, once the level is safe.
What's the difference between a glucose test and an A1C test?
A glucose test is a snapshot — your blood sugar at the moment of the draw, which shifts with meals, stress, and sleep. A1C reflects your average glucose over the past 2–3 months by measuring sugar attached to red blood cells. Clinicians often use both: glucose to catch the day-to-day picture and confirm fasting status, A1C (normal below 5.7%, diabetes at 6.5% or higher) for the long-term trend.
Check a different Glucose value
Sources
- Blood Glucose Test — MedlinePlus (National Library of Medicine)
- Diabetes Diagnosis & Tests — American Diabetes Association
- Hypoglycemia — Symptoms and Causes — Mayo Clinic
- Hyperglycemia in Diabetes — Symptoms and Causes — Mayo Clinic
- 6. Glycemic Goals and Hypoglycemia: Standards of Care in Diabetes—2024 — American Diabetes Association (Diabetes Care)
Educational information, not medical advice. Reference ranges vary between labs — always compare with the range printed on your own report and discuss results with your doctor. Full disclaimer