Health Information

Capillary nail refill test

Capillary nail refill test


Nail blanch test; Capillary refill time

The capillary nail refill test is a quick test done on the nail beds. It is used to monitor dehydration and the amount of blood flow to tissue.

I Would Like to Learn About:

  • How the Test is Performed

    Pressure is applied to the nail bed until it turns white. This indicates that the blood has been forced from the tissue. It is called blanching. Once the tissue has blanched, pressure is removed.

    While the patient holds their hand above their heart, the health care provider measures the time it takes for blood to return to the tissue. Return of blood is indicated by the nail turning back to a pink color.

  • How to Prepare for the Test

    Remove colored nail polish before this test.

  • How the Test Will Feel

    There will be minor pressure to the bed of your nail. This should not cause discomfort.

  • Why the Test is Performed

    Tissues need oxygen to survive. Oxygen is carried to various parts of the body by the blood (vascular) system.

    This test measures how well the vascular system works in your hands and feet -- the parts of your body that are farthest from the heart.

  • Normal Results

    If there is good blood flow to the nail bed, a pink color should return in less than 2 seconds after pressure is removed.

  • What Abnormal Results Mean

    Blanch times that are greater than 2 seconds may indicate:

    • Dehydration
    • Shock
    • Peripheral vascular disease (PVD)
    • Hypothermia

Related Information

  DehydrationShockPeripheral artery ...Hypothermia     Peripheral artery ...


White CJ. Atherosclerotic peripheral arterial diseases. In: Goldman L, Schafer AI, eds. Cecil Medicine. 24th ed. Philadelphia, Pa.: Saunders Elsevier; 2011:chap 79.


Review Date: 4/24/2013  

Reviewed By: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by A.D.A.M. Health Solutions, Ebix, Inc., Editorial Team: David Zieve, MD, MHA, Bethanne Black, Stephanie Slon, and Nissi Wang.

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