Nursing care
Hyperglycemia in Hospital, explained for the bedside and the exam
Written and reviewed by Dana Whitfield, RN, MSN · 4 min read · Updated September 2026
Short answer
Hyperglycemia in hospital is a blood glucose above 180 mg/dL in an inpatient, whether or not they have diabetes. Stress hormones, corticosteroids, and enteral feeds raise glucose in patients with no diabetes history. A sliding scale reacts to the number; only a scheduled basal dose controls the trend.
Defining it precisely
Inpatient hyperglycemia is defined as a blood glucose above 180 mg/dL, or a fasting value above 140 mg/dL, in any hospitalised patient. That threshold applies regardless of a prior diabetes diagnosis. A person with no history of diabetes can meet it on day two of an ICU admission.
The definition matters because it sets the trigger for action, not just the label. A postoperative patient with a glucose of 210 mg/dL meets criteria for treatment whether their A1c was ever checked or not. Treat the number and the context together, not the number alone.
The exceptions that matter
Surgical stress, sepsis, and trauma release cortisol, catecholamines, and glucagon. These push glucose up independent of insulin resistance from diabetes. A patient can be normoglycemic at home and hyperglycemic in the bed next to you within hours of a major bleed or a burn.
Corticosteroids given for anything, from a COPD exacerbation to a transplant, raise glucose predictably and often sharply, usually peaking hours after the dose. Continuous or bolus tube feeds add a steady carbohydrate load that a sliding scale, checked once every six hours, cannot track in real time.
The point that a generic hyperglycemia page misses: a sliding scale alone is chasing a number that has already moved. Scheduled basal insulin, dosed to match the steroid course or the feed rate, is what actually controls it. Correction doses fill gaps between basal coverage, they do not replace it.
Using it to prioritise
When a fingerstick comes back elevated, decide first whether this is a known diabetic on inadequate basal coverage, or a new stress-related rise in someone with no diabetes history. That distinction changes the plan, not just the correction dose.
In a patient on IV steroids or continuous tube feeds, an isolated high reading is not the priority; the trend across the shift is. Two or three readings climbing despite correction doses tells you the basal rate needs review, and that is a call to the prescriber, not another sliding-scale dose.
Hypoglycemia risk sits right behind hyperglycemia in priority. A patient whose tube feed is interrupted for a procedure, with basal insulin already given, is now at risk of a low. Reassess the plan the moment the feed stops, don't wait for the next scheduled check.
Traps in exam wording
Questions often present a patient with no diabetes history and a glucose of 200 mg/dL, then ask what the nurse should do. The trap answer assumes hyperglycemia only applies to known diabetics and dismisses the value as insignificant. It is significant, and it is stress-induced hyperglycemia until proven otherwise.
Another common wording gives a patient on a sliding scale with three consecutive elevated pre-meal readings and asks for the next nursing action. The distractor is 'administer another correction dose per scale.' The correct action is to notify the provider that basal dosing needs adjustment, because the sliding scale is not designed to fix a pattern.
Examples from practice
A patient on continuous enteral feeding via PEG tube has fingersticks running 220 to 260 mg/dL despite scheduled correction insulin. The feed rate has not changed. This is a basal insulin problem, not a correction-dose problem, and the fix is a scheduled basal order matched to the caloric load.
A patient started on IV dexamethasone for cerebral edema shows glucose climbing from 130 to 240 mg/dL over 48 hours with no diabetes history. Anticipate this rise before it happens, flag it to the provider early, and expect a temporary basal or correction regimen for the duration of the steroid course, not a one-off sliding-scale bump.
Summary
Hyperglycemia in hospital is not exclusive to diagnosed diabetics. Stress response, corticosteroids, and enteral feeding all raise glucose independently, and each demands scheduled basal coverage rather than reactive correction alone. A sliding scale treats what already happened; basal insulin prevents what happens next.
On the exam and at the bedside, the same principle holds: a pattern of elevated readings is a prescribing conversation, not a repeat correction dose.
The next step on this is the same as on everything else here: answer questions and read the rationales. Our reduction of risk potential practice questions are the closest set to what this page covers.
One question from the reduction of risk potential set
Four hours after a cardiac catheterization via the right femoral artery, the nurse notes the client's right dorsalis pedis pulse is now faint and the foot is cool and pale. What is the nurse's priority action?
Rationale
A pulse that was present and is now faint, with a cool, pale extremity distal to the puncture site, is arterial occlusion until proven otherwise — a limb-threatening complication that needs the provider now. Documenting and rechecking wastes the window, warming treats the symptom and masks the change, and asking the client to move the ankle neither restores flow nor gives you new information.
Answer: C
Common questions
Can hyperglycemia happen in a hospital patient with no diabetes?
Yes. Surgical stress, sepsis, corticosteroids, and enteral or parenteral feeding all raise blood glucose independent of a diabetes diagnosis. This is often called stress-induced hyperglycemia and it still meets treatment thresholds above 180 mg/dL.
Why isn't a sliding scale enough on its own?
A sliding scale corrects a glucose value after it has already risen. It does not anticipate the steady glucose load from a tube feed or a steroid dose. Scheduled basal insulin covers that ongoing load, which is why basal dosing is added once a pattern of highs appears.
What glucose value counts as hyperglycemia in an inpatient?
Generally above 180 mg/dL random, or above 140 mg/dL fasting, in any hospitalised patient. Individual institutional protocols and target ranges can vary, particularly in critical care, so check the unit's specific glycemic protocol.
What should a nurse do when three consecutive pre-meal glucose readings are elevated despite correction dosing?
Notify the prescriber that the basal insulin dose or the underlying regimen needs review. Repeating the correction dose without escalating the pattern leaves the patient under-covered until the next high reading.
Does stopping a tube feed change the insulin plan?
Yes. If a continuous feed is interrupted, for a procedure or otherwise, and basal or scheduled insulin has already been given, the patient is now at risk of hypoglycemia. Reassess glucose and adjust or hold correction dosing rather than waiting for the next scheduled check.
More on reduction of risk potential