When the heart beats, arteries pulse at the same time. Some of these arteries like the radial and carotid arteries can be felt easily, while others are too deep in the body to be accessed. This pulse measurement is an easy way of counting heartbeats, and this can be useful for determining things like resting or active heart rate.
As mentioned, two of the most common places to measure the heartbeat are at the carotid arteries, which are on the sides of the neck, and at the radial arteries. Pulsation of the radial arteries can be felt on the inside of the wrist. A good way to find this is to use the index and middle finger of the opposite hand. Follow the line of the thumb down until the wrist is reached. People will note bones at the wrist right below the thumb. Once these bones are passed, a small area of soft tissue is reached, and the radial pulse should be noticed. This is about an inch to half an inch (2.54 cm- 1.27cm) below where the hand meets the wrist on the thumb side, not directly in the center of the wrist.
When people take a radial pulse they make a common mistake of grabbing the wrist with the fingers and thumb. This can complicate trying to count pulse, because the thumb also pulses. Especially when taking the pulse of someone else, it's important to just use the first two fingers of the hand. Pressing too hard can be another mistake, as this might affect pulsation. When having difficulty finding a radial pulse, consider trying to find the pulsation of either of the carotid arteries instead.
In order to take an accurate radial pulse, a person will need access to a clock or watch that has a second hand. People are aiming to count the number of beats in a single minute, but usually, this can be at least estimated by counting beats for 10 to 15 seconds. The beats counted are then multiplied by six or four, respectively, to determine the appropriate minute heart rate count. Alternately some people take a radial pulse for six seconds and multiply the beats by 10. This last may be a little less accurate, and some do count the pulse for a full sixty seconds to get the best count of beats per minute (BPM).
There are number of reasons why people might want to take a radial pulse. They may be determining resting heart rate as per doctor’s orders, or alternately, they could be exercising and trying to determine whether they’ve reached their optimum heart rate for aerobic exercise. Alternately, people may need to the pulse of others who are unconscious, and this a common procedure when taking vitals in hospitals to check heart rate.