Blood sugar 139 mg/dL
139 mg/dL is above the normal fasting range and within the normal range for a standardized 2-hour 75 g oral glucose tolerance test (OGTT).
Where 139 sits
If this was a fasting reading
Diabetes rangeAs a fasting reading, 139 mg/dL is 13 mg/dL past the 126 mg/dL threshold labs use when diagnosing diabetes. One meter reading is not a diagnosis; labs confirm with repeat testing.
If this was a standardized 2-hour 75 g OGTT
NormalIn a standardized 2-hour 75 g oral glucose tolerance test (OGTT), 139 mg/dL is within the normal range: readings under 140 mg/dL are typical, and this one is 1 mg/dL under that line. These diagnostic categories apply to a laboratory OGTT, not an ordinary meal. Home monitoring targets are individualized with your care team.
Across the day
Across the day, 139 mg/dL sits inside the 70 to 180 mg/dL band that time in range is usually measured against.
What to do next
One reading is a data point. The useful question is whether 139 mg/dL is your usual or an outlier, and only a short run of readings can answer that: check at the same times for a week and look at the pattern, not any single number.
If fasting numbers keep landing high, start with how to lower fasting blood sugar. If meals are the pattern, see after-meal blood sugar spikes.
Pregnancy uses stricter targets. If you are pregnant, the ranges on this page do not apply to you; your care team will give you the numbers to aim for.
Nearby readings
General information, not medical advice. Reference ranges follow the ADA diagnostic criteria; a single meter reading is not a diagnosis, which requires laboratory testing, usually confirmed on two occasions. See how we calculate.
Stop looking numbers up one at a time
A page can tell you what a reading means in general. Your own log tells you what it means for you: log a reading in seconds and SteadyRange shows your logged readings in range and the patterns in your records, on a private log you control.
Sources and review status
Educational content maintained by the SteadyRange. Source and terminology check: September 30, 2026. Independent clinical review is pending; no clinical reviewer credentials are claimed.