Internal Medicine
Causes of High Blood Sugar Without Diabetes
Reviewed by the JordanMedHub Medical Editorial Team · 9/12/2026
Quick Answer
Blood sugar can rise temporarily for reasons that have nothing to do with diabetes — here's what else can cause it.
In this article
A high blood sugar reading doesn't automatically mean diabetes — several other factors can temporarily raise glucose levels, even in people who don't have the condition.
Common Non-Diabetic Causes
- Physical or emotional stress — stress hormones like cortisol and adrenaline can raise blood sugar temporarily
- Illness or infection — the body's stress response to being sick can elevate glucose
- Certain medications — including corticosteroids (steroids), some diuretics, and certain antipsychotics
- A large, carbohydrate-heavy meal — especially combined with inactivity afterward
- Dehydration — concentrates glucose in the blood
When It's Worth Getting Checked
An isolated high reading tied to an obvious cause like illness or stress usually isn't a concern on its own. But readings that are repeatedly high, or high without an obvious explanation, are worth discussing with a doctor — this is exactly the situation our prediabetes guide covers, since prediabetes and early type 2 diabetes are the most common underlying causes of persistently elevated blood sugar.
Disclaimer
This guide is for general education only and does not diagnose or recommend treatment for any individual. If you're seeing high blood sugar readings without an obvious explanation, talk to a doctor about testing.
Frequently Asked Questions
Can stress alone raise blood sugar?
Yes — stress hormones can temporarily raise blood sugar even without diabetes, though this is usually short-lived once the stressor resolves.
Written by JordanMedHub Medical Editorial Team
Updated 9/12/2026
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