You shouldn’t use your thumb to take a pulse because the thumb has its own noticeable pulse, which can make you confuse your own heartbeat with the one you’re trying to measure. The standard technique calls for using the tips of your index and middle fingers instead. That said, this is one of the most widely repeated rules in first aid and nursing, and the reasoning is worth understanding in detail.
The Artery in Your Thumb
Your thumb has a dedicated blood vessel called the princeps pollicis artery, which is the primary blood supply to the thumb. Unlike your other fingers, which receive blood through smaller shared vessels, the thumb gets its own relatively large artery. This means the pad of your thumb has a stronger, more detectable pulse than your index or middle finger.
When you press your thumb against someone’s wrist to feel their pulse, you may end up detecting two pulses at once: the patient’s and your own. If both happen to beat at similar rates, you might count your own pulse without realizing it. If they beat at different rates, the overlapping signals can make an accurate count nearly impossible. Either way, the measurement becomes unreliable.
Which Fingers to Use Instead
The Mayo Clinic recommends using the tips of your index finger and middle (long) finger together. Place them on the inside of the wrist, in the groove between the wrist bone and the tendon on the thumb side. You’re feeling for the radial artery, which runs close to the surface there. Press lightly until you feel a steady beat, then count.
The same two-finger technique applies when checking a pulse at the neck. Place your index and middle fingertips in the groove alongside your windpipe to feel the carotid artery. Avoid pressing too hard at this site, since the carotid is sensitive to pressure.
How Long to Count
Most nursing textbooks recommend counting for a full 60 seconds for the most accurate result. If you count for one complete minute, the number you get is your actual pulse rate, no math required.
In practice, many healthcare workers use a shortcut: counting for 15 seconds and multiplying by four. This is generally considered acceptable for a quick check, but it can magnify small counting errors. If you miscount by just one beat in a 15-second window, your final number is off by four. For routine self-monitoring at home, counting for 30 or 60 seconds gives you a more reliable number, especially if your heart rhythm feels irregular.
Other Places You Can Check a Pulse
The wrist and neck are the most common spots, but pulses can be felt at several other locations on the body. The brachial artery on the inner arm, just above the elbow crease, is commonly used to check pulses in infants during resuscitation. Other accessible sites include the inside of the ankle (posterior tibial artery), the top of the foot (dorsalis pedis artery), and behind the knee (popliteal artery). The same index-and-middle-finger technique applies at all of these locations.
Is the Thumb Rule Absolute?
Interestingly, a StatPearls review on peripheral pulse assessment notes that the traditional practice of avoiding the thumb during palpation “lacks support in the published literature.” No controlled study has definitively measured how often the thumb’s pulse actually causes miscounts in real clinical settings. The advice persists because it’s a simple, low-cost precaution: using your index and middle fingers eliminates a potential source of error, even if that error doesn’t happen every time. For anyone learning to take a pulse, following the standard technique removes one variable you don’t need to worry about.