Rate and rhythm
Feeling the pulse at the wrist is the oldest cardiac examination, and it still tells you four things: rate, rhythm, volume and character. The heart rate is simply how many beats per minute — a resting adult usually sits between about 60 and 100. Below that is bradycardia (which is normal and healthy in athletes); above it is tachycardia. Counting for a full 30 seconds and doubling, or 15 seconds and multiplying by four, is more accurate than counting fewer beats.
Rhythm is whether the beats are evenly spaced. A regular pulse with an occasional extra or dropped beat is common and usually benign. But a pulse that is irregularly irregular — no pattern at all to the spacing — is the bedside signature of atrial fibrillation. In atrial fibrillation some beats are too weak to reach the wrist, so the wrist rate can read lower than the true heart rate; that gap is called the pulse deficit.
Counting and the pulse deficit
Counting the heart rate from the pulse ---------------------------------------- Beats felt in 15 seconds = 19 Heart rate = 19 x 4 = 76 beats/min -> normal range (60-100) Pulse deficit in atrial fibrillation ---------------------------------------- Heart rate at the chest (by stethoscope) = 110/min Pulse rate at the wrist = 88/min Pulse deficit = 110 - 88 = 22 beats/min (some beats are too weak to open the aortic valve enough to be felt at the wrist)
Volume and character
Beyond rate and rhythm, the shape of each pulse wave carries information. A large, bounding pulse with a wide pulse pressure (a big gap between top and bottom blood pressure) suggests blood is leaving the heart fast — seen in fever, an overactive thyroid, or a leaking aortic valve. A small, slow-rising pulse that seems to build sluggishly is the opposite, and is a classic sign of aortic stenosis, where a tight valve throttles the outflow.
Comparing pulses on both sides, and between arms and legs, adds even more. A pulse weaker or delayed on one side hints at a narrowing or blockage in the artery feeding it. Checking the pulse is free, fast and quietly powerful — a reminder that good examination starts with the hands before any machine.