Skip to content

Sodium concentration in sweat

Published: August 9, 2026Updated: August 16, 2026

This test measures the amount of sodium (a mineral) found in your sweat, often used to diagnose conditions like cystic fibrosis or other sweat disorders.

Quick summary

["Assesses mineral balance in sweat, aiding diagnosis of genetic or metabolic conditions."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
2954-6
Short code
Sodium Sweat-sCnc
Synonyms
Sodium Sweat-sCnc
Category
electrolyte
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
136
Ref high
145
Critical range
120 N/A – 160 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
84295
SNOMED
110741000
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

Why Is This Test Done?

Your healthcare provider may order this test if you have symptoms like frequent infections, thick mucus, or unexplained sodium loss. It’s also used to monitor conditions like cystic fibrosis, where sweat sodium levels are consistently high.

What to Expect Before the Test

You’ll wear a special suit or bandages on your arms to collect sweat through a small tube. The process is painless and takes about 30–60 minutes. Avoid sweating excessively before testing by staying cool and avoiding strenuous activity.

What Happens During the Test?

A trained technician will apply a patch to your arm and collect sweat through a tube. The sweat is then sent to a lab for analysis. No needles or blood draws are involved.

What to Expect After the Test

You may feel a slight pressure or mild discomfort from the patch, but no lasting effects. Follow-up instructions may include avoiding certain foods or activities for a short time to ensure accurate results.

Reference range

Adult: 136-145 mmol/LN/A

Specimen: serum

No special preparation required. Stay well hydrated.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

High sweat sodium levels (above typical ranges) often indicate conditions like cystic fibrosis, where chloride and sodium are abnormally retained in sweat. Low levels may suggest other metabolic or genetic disorders affecting electrolyte balance. Results help guide treatment and management plans.

Short name

Sweat Sodium Level

Frequently asked questions

What does a high sweat sodium level mean?
A high sweat sodium level is often a key diagnostic marker for cystic fibrosis or other sweat gland disorders. It may also appear in conditions affecting sodium transport in the body, such as certain genetic mutations.
How is sweat sodium tested?
Sweat sodium is measured by collecting sweat through a specialized patch on your arm and analyzing it in a lab. The test focuses on the concentration of sodium in the sweat fluid, not in your blood.
Can diet affect sweat sodium test results?
Yes, diet can influence sweat sodium levels. Avoid salty foods or excessive sweating triggers (like exercise) before testing to ensure accurate results.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy