Is having a high blood sugar at 128 really high?

Blood sugar range applies to all ages - so your age is irrelevant.  The "normal" range doesn't change based on age group.

Normal blood sugar varies based on when  you test.

A fasting test (8 to 12 hours without carbohydrates) should between 75 to 99.

A test taken at two hours after a meal should be below 140.  (avoid testing too soon after a meal - you might catch a false high - your body needs some time to process what you just ate)

Any other random test that does not fit into those two should be between 80 to 120 to be considered normal.

If you are stressed or not feeling well, blood sugar levels can run a little high.  Certain medications can also make blood sugar levels run a little high.

Home testing meters do have a small variance and could be up to 20% off compared to the real reading.  Make sure your test strips are not expired.  Make sure your hands are clean when you test.  Testing errors can happen with home meters.

A single reading of 128 is usually nothing to worry about and that is NOT extremely high.  If you are concerned, then check your fasting readings for the next five days.  If your fasting readings are too far out of the normal range, then contact your doctor for a check up to be sure you aren't in the early stages of pre-diabetes.  

If this test was done by your doctor - the doctor might contact you if he/she feels that they should follow up with more testing.  But if this was not a fasting test - the doctor will very likely consider it normal also.  

That REALLY depends on when the blood test was carried out, ma'am.

A fasting blood glucose ... first thing in the morning, BEFORE you've had anything to eat or drink ... your blood sugar should be below 100 mg/dL.

Two hours post-prandial ... after you've eaten had something to drink ... your blood sugar level should be below 140 mg/dL.

Immediately after exercise you WILL notice that your blood sugar level will be increased ... unless it was heavy exercise performed for an extended period of time.  This occurs due to the production of epinephrine (adrenalin) from the adrenal glands.  They are unsure why you're exercising. i.e. are you preparing to fight an aggressor or preparing to run away?  In both cases your muscles require a ready supply of glucose (sugar) to 'fuel' them.

Diabetes II is a gradual failure that is completely reversible...until it becomes diabetes II. 

Once your pancreas is too damaged to properly cope, you're screwed.

I know what it is to not want to be addicted to something even though you are told by experts that it is hurting you and eventually will harm you, but your addict brain tries like hell to look for loopholes to continue further use.

Your addiction (even though you don't precisely know it) is fructose. 

no, that's in the 'normal' range ..................