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Biochemistry Kidney Home collection available

Osmolality, Serum

Parameters1 tested
SampleBlood
FastingNot required
Report inSame day

How to prepare

No fasting needed

You can eat and drink normally before the test.

Good to know

No special preparation needed.

Medicines

Tell our phlebotomist about any medicines you take. Don't stop them without asking your doctor.

Comfortable clothes

Wear a loose sleeve so the sample can be taken easily from your arm.

How it works

Book onlinePick a time slot
Home visitSealed, sterile kit
Lab testingBarcode tracked
ReportIn same day

About this test

Serum osmolality measures the concentration of dissolved particles (mainly sodium, sugar and urea) in blood. It helps assess water balance.

Why is this test done?

  • Investigate low sodium
  • Check for poisoning (alcohol, methanol)
  • Investigate excess thirst and urination

Symptoms — when should you get tested?

  • Confusion
  • Excess thirst
  • Dehydration
  • Suspected poisoning

Normal range

Adults 275 – 295 mOsm/kg

Reference ranges differ slightly between labs, methods, age and sex. Always discuss your report with your doctor.

If your result is high

High osmolality means the blood is too concentrated.

Common reasons
  • Dehydration
  • High sugar
  • Diabetes insipidus
  • Alcohol or methanol poisoning

If your result is low

Low osmolality means the blood is too dilute.

Common reasons
  • SIADH
  • Drinking excess water
  • Heart, liver or kidney failure

How is the test done?

  1. 1
    Book online

    Choose your slot for home collection or a visit to our centre.

  2. 2
    Blood sample taken

    A trained phlebotomist takes a small blood sample from a vein in your arm with a sealed, single-use needle. It takes about 2 minutes.

  3. 3
    Tested in our lab

    Your barcoded sample is tested on automated machines with strict quality checks.

  4. 4
    Report on WhatsApp

    A pathologist checks the result and the report reaches you on WhatsApp and email.

Frequently asked questions

No fasting is needed for this test. You can eat and drink normally.

Your report is usually ready in same day after the sample reaches our lab. We send it on WhatsApp and email, and you can also download it from the Reports page.

Please call our team to confirm whether home sample collection is available for your location and test.

This test needs a blood sample. No special preparation needed.

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