Capillary refill is a simple, non-invasive diagnostic procedure to test peripheral circulation. It can be used on anyone from an infant to an unconscious patient.
To perform the test, the physician raises one of the patient's hands above the level of the patient's heart. The physician then applies pressure with a finger to a soft part of the patient's fingertip or fingernail until it turns white. In a newborn infant, the physician can press the skin above the sternum instead. The pressure is then released and the time to recovery to full normal color (compared to the rest of the skin) is measured.
A normal response is less than two seconds in most individuals, or less than three seconds in an infant.
A slower than normal response time can point to several conditions including shock, dehydration or peripheral artery disease. However, as many factors can affect the test results, the test is not very definitive in establishing a diagnosis, although due to its simplicity, it is useful in working out possibilities in a differential diagnosis.