Why you should not take a pulse with your thumb

Why your thumb can confuse a pulse check

The thumb has its own blood supply, including an artery that can produce a noticeable beat. When you press it against someone’s wrist, you may feel that beat through your thumb rather than the other person’s artery. The two rhythms can seem similar, making it easy to count your own pulse by mistake.

Use two fingertips instead

For a wrist check, place the pads of your index and middle fingers on the thumb side of the other person’s inner wrist. Press gently until you feel the artery’s rhythm. Those fingers are less likely than your thumb to give you a strong competing pulse, so the beat you detect is more likely to be theirs.

Avoid pressing so hard that you flatten the artery; a pulse is easiest to feel when blood can still move through it. If you cannot find it at first, shift your fingertips slightly rather than pushing harder. The practical payoff is simple: keeping your thumb out of the check helps make sure the rhythm you count belongs to the person you’re assessing.