Blood Sugar higher than before on Insulin

by Michelle
(Tucson, Arizona, USA )




Quick Answer
Assuming the readings are in mmol/L, 7.8 is about 140 mg/dL and 9.0 is about 162 mg/dL. A higher reading after starting insulin does not prove that insulin caused the rise or that the dose is too high. Basal insulin is often started at a conservative dose and increased gradually according to fasting glucose. The Somogyi effect should not be assumed; it is much less common than insufficient overnight insulin or the dawn phenomenon. Do not change the dose independently, but ask the prescriber to review the glucose pattern, insulin type, timing, injection technique, and risk of overnight lows.


Answer by Dr. Albana Greca, MD, MMedSc



Hello Michelle,



It is understandable to be concerned when your mother’s glucose appears higher after beginning insulin. However, insulin does not normally make glucose rise. A common explanation is that the starting dose is not yet enough, the timing does not match her glucose pattern, or the higher readings are being measured at a different time than before.



Is Increasing Insulin Common?



Yes. Basal insulin for type 2 diabetes is often started at a low dose and then titrated according to fasting glucose and the person’s response. A change from 10 to 20 units may be appropriate for some people, but the safety of that change depends on the insulin type, body weight, kidney function, eating pattern, glucose records, and whether any low readings have occurred.



Your mother should follow the written plan from her prescriber and should not increase, reduce, or skip insulin on her own. Our insulin treatment guide explains the roles of basal and mealtime insulin.



Do Not Assume the Somogyi Effect



The original answer diagnosed the Somogyi effect without enough information. That cannot be determined from one morning reading. The more common causes of morning hyperglycemia are:




  • Insufficient or waning basal insulin: The dose may be too low or may not last until morning.

  • Dawn phenomenon: Early-morning hormones can signal the liver to release glucose.

  • Food or medicine timing: A late meal, snack, missed dose, or different test time can change the result.

  • Illness or other medicines: Infection, pain, stress, or corticosteroids may raise glucose.

  • Injection problems: Incorrect technique, repeated use of lumpy areas, spoiled insulin, or poor storage can make insulin less reliable.



Our page on high morning blood sugar explains the difference between dawn phenomenon, insufficient insulin, and overnight hypoglycemia.




Important: Increasing bedtime insulin without checking the overnight pattern may cause nocturnal hypoglycemia in some people. The decision should be based on several readings, not one result.


How Can the Cause Be Identified?



For several days, record glucose at bedtime, during the night if the clinician recommends it, and on waking. A continuous glucose monitor can provide even more useful information. If glucose is already high overnight, the dose or timing may be insufficient. If it is normal overnight and rises toward morning, dawn phenomenon is more likely. If there is a true overnight low, the treatment plan needs review before insulin is increased.



Also record the insulin name, dose, injection time, meals, snacks, activity, illness, and any symptoms. Compare readings with the general ranges in our blood sugar level chart, while following her personal target.



Check the Insulin and Injection Technique




  • Confirm the exact insulin name and whether it is basal, premixed, or mealtime insulin.

  • Use the prescribed dose at the prescribed time.

  • Check the expiration date and storage instructions.

  • Use a new needle and confirm the pen or syringe is working correctly.

  • Rotate injection sites and avoid hard or lumpy areas.

  • Make sure the full dose is delivered and the needle is kept under the skin for the recommended time.



Persistent high readings despite insulin should lead to a structured review rather than an automatic diagnosis of Somogyi effect. See why blood sugar may remain high despite insulin.



Should She Get a Second Opinion?



First, ask the current doctor to explain:




  • Which readings are being used to adjust the dose

  • Her fasting and bedtime glucose targets

  • How quickly the insulin should be increased

  • What to do if glucose falls below 70 mg/dL

  • Whether overnight checks or CGM are needed



A second opinion is reasonable if the explanation remains unclear, the prescribed change feels unsafe, she has repeated low readings, or glucose continues to rise despite correct use. Do not delay necessary treatment while arranging it.



When Is Urgent Help Needed?



A reading around 9 mmol/L, or 162 mg/dL, is above target for many people but is not usually an emergency by itself. Seek prompt help for repeated severe hyperglycemia, dehydration, vomiting, abdominal pain, fruity breath, deep breathing, confusion, or moderate-to-high ketones.



Review low-glucose symptoms and treatment in low blood glucose causes and treatment.



My Advice



Do not conclude that your mother has the Somogyi effect from the information given. Dose titration after starting insulin is common, but the increase should be based on a clear glucose pattern and a written safety plan. Ask her doctor to review several days of readings, insulin technique, timing, meals, and overnight glucose before deciding the best dose.



Hope this helps.



Dr. Albana Greca



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References






Educational only — not personal medical advice. Insulin doses should be changed only according to an individualized plan. Recurrent lows, severe highs, or symptoms of a diabetes emergency require prompt medical care.


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