what is a normal level for the sweat test?

[anonymous]

I have read different levels. It appears that over 60 is positive for CF. But I've seen borderline as both 50 and above, and 40 and above. Is a level in the mid 40's considered borderline? I read somewhere that 22 was a "normal" level.

 

[anonymous]

You are going to hear a lot of different things on this site about this because every doctor thinks differently. If it were me, personally, I would re-test at 30 and do a blood test.

 

[NoDayButToday]

I think between 40-60 is officially considered borderline, above 60 positive and below 40 negative. However, if it is in the high 30s and a kid is exhibiting a lot of CF symptoms, I'd get a retest or more extensive testing.

 

[anonymous]

I just did some research and found out that there are 2 main types of testing and corresponding normal ranges. A measurment of chloride versus a measurement of conductivity. The ranges vary by 15 mmol/L. Therefore a conductivity reading of 45 would equate to a chloride measurement of 30. And it appears that about 50% measure one vs the other. My children measured 39 and 43. I was concerned because they were in the boderline range. So I called the hospital where they were tested to find out they measure conductivity. Therefore these numbers actually equate to 24 and 28 on the chloride scale. The conductivity high is 80 and above with 60 being borderline. FYI for anyone else going through the testing.