Blood Sugar 105 mg/dl — Normal or Too High? Both Answers
Where 105 mg/dl sits — adjust to your situation
105 mg/dl as a fasting reading
Prediabetes range
A fasting reading between 100 and 125 mg/dl falls into the prediabetes range. One reading is not a diagnosis — but it is a signal worth confirming with your doctor.
Fasting = no food for at least 8 hours, typically first thing in the morning. More on fasting readings.
105 mg/dl after eating
Normal
Up to 139 mg/dl two hours after starting a meal is a normal response: your body is clearing glucose from the blood on schedule.
Guidelines measure 2 hours after the start of a meal. More on post-meal readings.
Feeling completely well with a fasting 105 is normal
Many people who see 105 mg/dl on their meter say the same thing: “But I feel fine.” That is expected. Impaired fasting glucose in the low 100s almost never causes symptoms. No thirst, no tiredness you could pin on it, no change in how often you visit the bathroom. Most people with prediabetes find out by chance, through a routine blood test or a meter borrowed from a relative.
The absence of symptoms is not proof that the number is meaningless. It only means the body is still coping well enough that nothing shows from the outside.
Why the body stays quiet at this level
The classic warning signs of high blood sugar, such as constant thirst, passing large amounts of urine and unexplained weight loss, appear when glucose rises so far that the kidneys can no longer hold it back. That usually happens only once blood levels pass roughly 180 mg/dl. Glucose then spills into the urine and pulls water with it.
At 105 you are far below that point. Insulin still does most of its job. It may need a little more effort to keep fasting levels in check, which is exactly what the number is hinting at. Changes inside blood vessels or the liver at this stage are silent too, which is why screening exists in the first place.
Questions to bring to your appointment
Because you feel fine, it is easy to postpone a visit. A short list makes the appointment worth it:
- Should my fasting result be confirmed with a lab fasting glucose, an A1C, or both?
- Do my weight, waist size, blood pressure or cholesterol add to my risk?
- Does anyone in my family history change how closely I should be followed?
- Could any of my current medicines be raising my glucose?
- Is an oral glucose tolerance test useful in my case?
- Am I eligible for a structured lifestyle program based on the Diabetes Prevention Program?
- When should I be retested if the results are normal or borderline?
Bring a few home readings with dates and times. If you want background before the visit, the overview on prediabetes covers the main tests.
Silent does not mean fixed
A symptom-free 105 can go in several directions over the years. Many people stay at about this level for a long time, some drift back into the normal range, and some move higher toward the diabetes threshold. Which path you follow depends partly on things you can influence, such as activity, weight around the waist, sleep and what you eat in the evening. Because you will not feel the difference between those paths, the only way to know which one you are on is to recheck at regular intervals.
Measured right after exercise?
There is no official range for readings taken during or just after a workout, so the two classifications above do not apply to them. How exercise moves blood sugar.
How 105 mg/dl compares to a typical day
Typical day without diabetes; your reading is the horizontal line — within the range a normal day passes through; when you measured decides how it counts.
What to do with a reading of 105 mg/dl
Confirm with a second test on another day and talk to your doctor about an A1C test. Modest weight loss and a daily walk measurably lower readings in this range.
What actually moves the number: How to lower blood sugar, Foods that steady your glucose and Exercise and blood sugar.
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Questions about 105 mg/dl
Is 105 mg/dl blood sugar normal?
It depends on when you measured. Fasting, 105 mg/dl is prediabetes range (normal fasting range: 70–99 mg/dl). Two hours after a meal it is normal (normal post-meal range: 70–139 mg/dl).
What is 105 mg/dl in mmol/L?
105 mg/dl equals 5.8 mmol/L. Divide mg/dl by 18 to convert (used in the UK, Canada, Australia and most of Europe).
How far is 105 from a normal fasting level?
You are 6 mg/dl above the top of the normal fasting range (99 mg/dl). Changes in this range are very achievable: in the Diabetes Prevention Program, diet and activity cut progression to diabetes by more than half.
How accurate is a home reading of 105 mg/dl?
Home meters are allowed an error of ±15 mg/dl below 100 mg/dl and ±15 % from 100 up (ISO 15197), so a displayed 105 can correspond to a true value anywhere from 89 to 121 mg/dl. Fasting, that window crosses the 100 mg/dl line — a single home reading of 105 cannot settle which side you are truly on. That is a lab-test question, not a meter question.
What A1C would 105 mg/dl correspond to?
If 105 mg/dl were your average glucose over three months, it would work out to an A1C of about 5.3 % — in the normal A1C range (below 5.7). A single reading is not an average — but the conversion shows what this level would mean as a habit. How the two measures relate: A1C and blood sugar.
Can tiredness or tingling feet come from a fasting 105?
These complaints are not typical for glucose in this range, and they have many other possible causes, from sleep problems to vitamin deficiencies. Mention them to your doctor anyway. Describing them separately from the glucose result helps the doctor look for the real reason.
If I have no symptoms, how would I notice if things got worse?
Mostly through testing, not feelings. Regular lab checks, typically once a year with prediabetes, catch a rise long before thirst or weight loss would. A home meter used now and then under the same fasting conditions can add an early hint between visits.
BloodSugarEasy — blood sugar reading report
Reading: 105 mg/dl (5.8 mmol/L)
Fasting classification: Prediabetes range · After-meal classification: Normal
Reference: ADA criteria, reviewed 2026-11-03 · https://bloodsugareasy.com/blood-sugar-105/
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