Sweat test (sweat chloride)


Sweat test (sweat chloride)

Site(s) or Laboratory offering Test/Investigation





Please contact laboratory (NNUH)

Sample type

Sweat collection arranged by the Respiratory Paediatrics Team

Turnaround times (TAT) Urgent/Routine/GP or OPD

Test performed on Wednesdays only, unless by prior arrangement

Reference intervals (adult unless stated)

As per 2014 guidelines 'Performance of the Sweat Test for the Investigation of Cystic Fibrosis':
A sweat chloride concentration of > 60 mmol/L supports the diagnosis of CF.
A chloride concentration of 40 – 60 mmol/L, or if less than 6 months of age 30 – 60 mmol/L, is an intermediate result which requires further cystic fibrosis assessment such as a repeat test and/or further investigations.
A sweat chloride of < 40 mmol/L (or < 30 mmol/L in patients less than 6 months of age) makes CF unlikely but requires genetic and clinical correlation.

If UKAS Accredited Test indicate at which site



Guidelines for the performance of the Sweat Test for the Investigation of Cystic Fibrosis in the UK v.2 (2014). http://www.acb.org.uk/docs/default‐source/committees/scientific/guidelines/acb/sweat‐guideline‐v2‐1.pdf (accessed 05/05/2022)