If your fasting test was 166 are you immediatly diagnosed or do you have to do another fasting test?

2 strike count. Down in the ball count but still swinging. You need: fasting sugar of 126 or more or A1c of 6.5 or more or 2 hour fasting glucose test of 200 or more. No high sugar symptoms? You need 2 abnormal tests. If you have 1 abnormal test and 1 normal different test, then you repeat the abnormal test on different day. High fasting sugar &, normal a1c, repeat high fasting sugar is 3rd strike.
Likely so. However, you will need to compile a 2 week data with added bedtime glucose reading before discussing it with your physician. Make sure you have the right code on the glucometer screen (if required) and to wash hands with warm water and soap before each check.
Need another. By criteria, you need another positive test to give you the diagnosis of diabetes. You could do another fasting test or better yet a hemoglobin A1c test (a blood draw). This test gives you your sugar average for the last 2-3 months and can tell you the severity of the diabetes.
Yes. It is best not to relie on only one test to make a diagnosis of a chronic condition. The test should be repeated. There is always the outside possibility that it was an error.