What does "deviation" mean?


Patients Diabetes (Type 1)

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Posted on

Hi guys. So I'm having a hard time understanding what deviation means (we'll call it a blonde moment lol) when I looked it up it said it basically means it's the difference on either side of your average blood sugar. But I looked on my app it says my average blood sugar for the day is 79mg/dl with a deviation of +/-15mgdl but one of my blood sugars was 104 (which obviously isnt a bad number) but thats bigger than a 15 point difference. I'm so confused and it's probably something so simple lmao. I'll post a pic for reference.

(App is mysugr) 

Beginning of the discussion - 8/18/18

What does "deviation" mean?

Posted on


You are correct with your understanding of "deviation." However, the deviation applies to the average, thus your average blood sugar for the day can be +/- 15 mgdl from 79. So basically, your average blood sugar rating could be between 64 - 94. The smaller the deviation the better.

So do not think of it as +/- 15 from any one blood sugar test. The more fluctuation in your blood sugar tests throughout the day will likely lead to a higher deviation... does that make sense?

What does "deviation" mean?

Posted on

@naptnm yes it does. Tysm! 

What does "deviation" mean?

Posted on


Glad I could help. Their support staff is good also, so if there is ever a question and you need a quick answer, dont hesitate to contact them also.

Have a good day!

What does "deviation" mean?

• Community manager
Posted on

@naptnm‍ Thank you for your response to @sarahsmilesx3‍.

@naptnm‍ your response is spot on. I also contacted the mysugr support team for your question the day you posted it @sarahsmilesx3‍ and today I got a response. It is basically what @naptnm‍ stated, but a bit more in detail. Please find the response to my question "about what deviation on the mysugr app means" below:

"Hi there!
Thank you for your message and taking the time to write us!

We use the following formula:
sqrt ( sumSquare - (sumMeasurements * averageMeasurement) / numberOfMeasurements )

- sumSquare is the sum of all squared measurements
- sumMeasurements is the sum of all measurements
- averageMeasurement is the average of all measurements
- numberOfMeasurements is the number of measurements
- sqrt is the square root

Standard Deviation is all about how much your blood sugar swings up and down - or how much it varies from your target on average. It's a good way to know if your average blood sugar is a true reflection of good control, or if it's a mix of many highs and lows.

I hope that helps - please let me know if you have additional questions about it! ?‍


Jennifer Haverkamp | Happiness Hero"


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