If you have enough strips, it's an interesting experiment to test every finger and compare. You'll find that you can get different #s on every one. My best # is always on my left forefinger. I know we have some really great folks here with more experience than I who can explain it.
Judith, I'm going to try that, and log my numbers. Thank you for the sugestion.
That happened to me the other day. One number was a little high, and I thought that was odd, considering I hadn't had anything to eat in over 4 hours, and my two hour bg after eating breakfast was fine. But I had 3 completely different numbers on all 3 fingers. My only guess was that 20 +/- variation. I agree it IS weird, lol.
I am glad you asked.
I have seen similar responses. I notice that if I check other fingers on the hand with the highest reading, I will find other fingers whereby the readings vary from 0 to 10 points from the lower reading on the other hand.
I usually average the two readings and always retest if difference is higher than 15 points.
Also this difference is worst when I am not exercising - sitting working on computer. Usually after walking the numbers move closer together.
The other farce not mentioned elsewhere is that your liver and gut dump in the glucose and not necessisarily metered on to your blood system and the even mixing only occurs when after the heart has pumped the lot around your body a few times mixing it up. No, your readings will not be the same all over your body at same time contrary to the experts.
If you want some fun, munch some glucose tablets and immediately watch your glucose readings one after another on your fingrtstick machine at your finger tip and do not have a miocardial infarction as you watch the glucose hammered onto your blood system and see how long it takes to get stabalized back to "average " readings.
Lady Elders---if you have enough test strips, try the same thing as your hot flash climbs, peaks and recedes. My travels up 20 points or more and slowly settles back......
Yikes, never tried that! I think I'll pass LOL
The typical deviation of test stripes is stated in the manual. Typically it is 20% and this means the result from the same drop of blood can deviate by 20% of the actual blood glucose. Actually I do not think that there can be a systematic difference between the hands.
Holger, my friend---don't laugh-or do!---but out of curiosity once, well, one of my kitties jumped off my lap and left a scratch on my thigh behind and so I stuck a strip to it and then tested my "favorite" finger, too. They were indeed within 10 points of each other. How could I help myself---cats and curiosity, you know!......
Hahaha gotta love cats!!!
I was raised with cats and my parents still have a norwegian forest cat and a turkish van. The most non functional combination of cat races I could think of (balance vs temperament). Of course a scratch was always a good reason for testing. With cats I learned to hide my used stripes away. They think that these bloody things are some kind of catch to chew on Ugh!
I tested on all my fingers this morning, there was a 10 point difference in each hand. however, there was only 2 to 5 point difference in each finger on my right vs 4 to 9 on my left hand. My right hand ring finger is the most accurate.
How do you know that your right hand ring finger is most accurate? Statistically every test has a deviation of +/- 20%. In statistics your small number of tests can not proof your point. In some experiments people are asked to invent the result of throwing a coin (head VS number: 1 VS 0) 100 times. When the invented sequence is compared with the result of randomized experiments you will see that people tend to leave out unlikely cases. So they will hesitate to invent the sequence 111111111111111111111111111111111 although it is not unlikely. In the randomized experiment you will find these unlikely sequences for sure. What I want to say is that:
a) every test result of a stripe is independent from the previous result. Every single test can be expected to deviate up to 20% from the real number. But the deviation itself is a random act.
b) contributing factors: environmental temperature will influence blood circulation, water balance and the catalythic reaction in the stripe. Residue containing carbs on the surface of the finger can influence the outcome. Also with hands in not perfectly dry condition the residual moisture can influence the result. Even the way you squeeze your finger is important. With much force you will increase the tissue/plasma fluid and by hitting a blood vessel more directly you will have more whole blood. The type of blood will influence the proportion of glucose in the fluid. Here the manufacturers just decided that it is more likely to draw plasma fluid from the fingers. Thus they have calibrated their equipment on plasma fluid. As you can see we have some factors involved.
c) even if you compare your results with lab equipment you will have to face the fact that lab equipment has a deviation too. It is smaller but deviation still occurs. So the lab equipment can say 100mg/dl with a deviation of +/- 5%. This means the real BG can be 105 or 95 mg/dl. This means that the test stripe can result in 80 or 120 mg/dl with the same blood and this would be perfectly accurate according to the nature of the measurement. It also means that two tests in a row with 100 and 102 are possible. But this does not mean that the stripes or fingers are more accurate. It just means that the deviation is just a random inaccuracy we will have to live with.
I think it is pretty sure that the deviation numbers of manufacturers are exaggerated to protect themself from liability issues. Some manufacturers even manage to have more accurate results although their manual states it differently. For market clearance they have to meet FDA and EU standards and they will make sure to take that hurdle without problems. In my opinion it is about time to reduce the deviation even more but this decision is up to FDA and EU. At the end this is also a question of cost increase VS accuracy increase and its benefits.