Which digit should not be used to take a pulse?

The thumb should not be used to take a pulse because it has its own pulse due to the presence of a large artery running through it. When you use your thumb to check for a pulse, you may confuse the pulse you feel in your thumb with the pulse of the patient, leading to inaccurate measurement.

The pointer finger, index finger, and middle finger can all be used effectively for this purpose, as they do not have significant blood flow that could interfere with the assessment of another person's pulse. Using these fingers facilitates a clearer and more reliable sensing of the pulse rhythm and strength, which is crucial for proper assessment of a patient's heart rate and overall cardiovascular status.