Blood Sugar 145 mg/dl — Too High? Fasting & After Eating
Where 145 mg/dl sits — adjust to your situation
145 mg/dl as a fasting reading
Diabetes range
A fasting reading of 126 mg/dl or higher falls into the diabetes range. Diagnosis requires a repeat test on another day — take this result to your doctor.
Fasting = no food for at least 8 hours, typically first thing in the morning. More on fasting readings.
145 mg/dl after eating
Prediabetes range
Between 140 and 199 mg/dl two hours after a meal suggests impaired glucose tolerance, the post-meal form of prediabetes.
Guidelines measure 2 hours after the start of a meal. More on post-meal readings.
A 145 on the glucose tolerance test report
The oral glucose tolerance test, or OGTT, is the standard way to see how your body handles a sugar load. If the two-hour value on your lab report reads 145, the result falls into impaired glucose tolerance, the after-meal form of prediabetes. The cut-offs are: under 140 normal, 140 to 199 impaired, 200 or more in the diabetes range. A lab value of 145 is measured on a precise analyzer, so unlike a home reading it is not within shouting distance of meter error. It is five points over the line.
That does not make 145 a diabetes result. It is a signal that clearance after a sugar load is slower than it should be, and an invitation to act while the change is still easy to reverse.
How the 75 g test works, step by step
- The days before: eat your usual diet with normal amounts of carbohydrate. Low-carb eating just before the test can make the result look worse than it is.
- Overnight fast: nothing but water for at least eight hours, usually ten to fourteen. Arrive in the morning.
- First blood draw: a fasting glucose is taken from a vein.
- The drink: you drink a solution containing 75 g of glucose within about five minutes. It is very sweet; some labs offer it chilled.
- The wait: you sit quietly for two hours. No food, no smoking, no walking around the block.
- Second blood draw: exactly two hours after you started drinking. Some protocols take samples at one hour as well.
Bring something to read and a snack for afterwards. A few people feel queasy or light-headed during the test; tell the staff if that happens.
Why the test reveals more than a fasting check
A fasting glucose shows how well the liver holds back its sugar release overnight. The OGTT adds a challenge: 75 g of pure glucose delivered all at once, on an empty stomach. It shows how quickly insulin is released and how well muscle responds. Some people with a normal fasting value and a normal A1C only show a problem on this test. That is why doctors sometimes order it when risk factors are strong but simpler tests look fine.
The test has drawbacks too. It takes a whole morning, results vary a little from day to day, and illness or recent bed rest can make it look worse. For that reason a result in the diabetes range is confirmed with a second test. For a 145, many doctors add an A1C to complete the picture and to have a simple number to follow over the years.
After an OGTT of 145
The standard advice is the same as for other forms of prediabetes: the Diabetes Prevention Program approach of about 7 % weight loss and 150 minutes of weekly activity, which cut progression to type 2 diabetes by 58 %. Re-testing is generally suggested at least once a year. The prediabetes page goes through the options.
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 145 mg/dl compares to a typical day
Typical day without diabetes; your reading is the horizontal line — higher than a typical day reaches two hours after a meal; brief one-hour peaks this high are common.
What to do with a reading of 145 mg/dl
Book a doctor's appointment to confirm with a lab test (fasting glucose or A1C). If you are already diagnosed, this reading belongs in your log for your care team.
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 145 mg/dl
Is 145 mg/dl blood sugar normal?
It depends on when you measured. Fasting, 145 mg/dl is diabetes range (normal fasting range: 70–99 mg/dl). Two hours after a meal it is prediabetes range (normal post-meal range: 70–139 mg/dl).
What is 145 mg/dl in mmol/L?
145 mg/dl equals 8 mmol/L. Divide mg/dl by 18 to convert (used in the UK, Canada, Australia and most of Europe).
Does one reading of 145 mg/dl mean I have diabetes?
No single home reading is a diagnosis. Guidelines require a second abnormal lab result, either a different test from the same blood draw or a repeat on another day (fasting glucose, an oral tolerance test, or A1C). But a reading like this is exactly the reason those tests exist — take it to your doctor.
How accurate is a home reading of 145 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 145 can correspond to a true value anywhere from 123 to 167 mg/dl. Fasting, that window crosses the 126 mg/dl line — a single home reading of 145 cannot settle which side you are truly on. That is a lab-test question, not a meter question. After a meal, the window touches the 140 mg/dl boundary.
What A1C would 145 mg/dl correspond to?
If 145 mg/dl were your average glucose over three months, it would work out to an A1C of about 6.7 % — at or above the 6.5 % diabetes threshold. 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.
Why must I sit still during the two hours?
Walking uses muscle glucose and lowers the result, while stress and smoking can raise it. The cut-offs were set for people sitting quietly, so moving around would make your value impossible to compare with them.
My home reading after breakfast is usually 110, but the OGTT gave 145. Why?
The test drink is pure glucose on an empty stomach, with no fiber, fat or protein to slow it. Most breakfasts contain less fast sugar and are digested more slowly. The OGTT is a deliberate stress test, so it often shows a higher value than everyday meals.
BloodSugarEasy — blood sugar reading report
Reading: 145 mg/dl (8 mmol/L)
Fasting classification: Diabetes range · After-meal classification: Prediabetes range
Reference: ADA criteria, reviewed 2026-11-03 · https://bloodsugareasy.com/blood-sugar-145/
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