High glucose in morning

by Kathy Cullen
(Coral Springs fl)




Question: Hello,


When I go to bed my sugar is 130 to 140. When I wake up it is 185. I don’t eat carbs and take Jardiance and Januvia to control my diabetes.


What’s happening here?




Quick Answer



Your glucose may rise overnight even when you do not eat. The most likely explanation is the dawn phenomenon: early-morning hormones signal the liver to release glucose, and diabetes limits the body’s ability to control that rise.


A fasting reading of 185 mg/dL is above the common before-meal target of 80–130 mg/dL for many nonpregnant adults with diabetes. Record the pattern and arrange a treatment review, but do not change Jardiance, Januvia, or their doses on your own.




Answer by: Dr. Albana Greca Sejdini, MD, MMedSc



Why Can Glucose Rise While You Sleep?


The liver releases glucose between meals and overnight so the body has energy. Before waking, hormones such as cortisol, glucagon and growth hormone can increase this release. In people with type 2 diabetes or insulin resistance, the available insulin effect may not be sufficient to keep morning glucose within target. This is called the dawn phenomenon and is a common reason for high blood sugar in the morning.



Other possible contributors include:



  • A late dinner, bedtime snack or more carbohydrate than expected

  • Poor sleep, sleep apnea, emotional stress or pain

  • Illness, infection, dehydration or reduced activity

  • Steroid medicines or another medicine that raises glucose

  • Diabetes treatment not controlling overnight liver glucose adequately

  • Meter, strip, hand-washing or testing-timing problems



Is This the Somogyi Effect?


An overnight low followed by rebound morning hyperglycemia is often called the Somogyi effect, but it appears to be less common than the dawn phenomenon. Jardiance (empagliflozin) and Januvia (sitagliptin), when used without insulin or a sulfonylurea, usually have a low risk of causing hypoglycemia. Therefore, an overnight low should not be assumed.


A continuous glucose monitor is the clearest way to see the overnight pattern. Alternatively, your clinician may ask you to compare bedtime, approximately 2–3 a.m., and waking readings on several nights. One nighttime check cannot establish the cause.



Important Jardiance Safety Note



“I don’t eat carbs” may mean a very-low-carbohydrate or ketogenic eating pattern. While taking Jardiance, very-low-carbohydrate diets, prolonged fasting, dehydration and acute illness can increase the risk of diabetic ketoacidosis (DKA). DKA related to an SGLT2 inhibitor can occur even when glucose is below 250 mg/dL.


Do not stop or restart Jardiance routinely without medical advice, but ask your prescriber for written sick-day and fasting instructions. A balanced diabetes eating plan does not require eliminating all carbohydrate.




What to Do Next



  1. Repeat fasting readings on several mornings after washing and drying your hands; use unexpired strips.

  2. Record bedtime, overnight if advised, and waking glucose, along with dinner, medicine timing, sleep, illness and activity.

  3. Review your A1C and glucose log with the clinician prescribing Jardiance and Januvia. Repeated fasting values near 185 mg/dL may require a change in the overall treatment plan.

  4. Stay adequately hydrated unless you have been given a fluid restriction for heart or kidney disease.

  5. Do not add a bedtime snack, increase medicine or change doses until the overnight pattern has been reviewed.


Our blood sugar levels by time of day guide explains how fasting, before-meal and after-meal readings are interpreted.




When to Get Urgent Help


While taking Jardiance, seek urgent medical care for nausea, repeated vomiting, abdominal pain, unusual exhaustion, confusion, deep or difficult breathing, fruity-smelling breath, inability to keep fluids down, or positive ketones—even if glucose is not extremely high. Also seek prompt advice if glucose remains above 300 mg/dL despite following your prescribed plan.




Related Questions




Related Resources




Medical References




Answered by: Dr. Albana Greca Sejdini, MD, MMedSc

Medically reviewed by: Dr. Ruden Cakoni, MD, Endocrinologist

Last reviewed: July 2026


Medical disclaimer: Educational only—not personal medical advice. Diagnosis and treatment should come from a qualified clinician who knows the patient’s medical history.


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