A pulse is the rhythmic pressure wave created when the heart pumps blood through the arteries. Monitoring this wave provides a simple, non-invasive method for assessing the performance of the cardiovascular system. The radial pulse is the specific pulse felt at the wrist. This pulse reflects the heart rate, or the number of times the heart beats per minute, and offers insights into the heart’s rhythm and the strength of blood flow.
Finding the Pulse Point
To correctly locate the radial pulse, the subject should be resting comfortably, and the wrist should be slightly extended with the palm facing up. The radial artery is situated on the thumb side of the inner wrist, running along the distal end of the radius bone. This location is preferred because the artery lies superficially.
The proper technique for palpation involves using the pads of the index and middle fingers of the opposite hand. Avoid using the thumb, as it has its own prominent pulse that can be mistaken for the subject’s. Gently place the fingertips in the groove on the thumb side of the wrist, about an inch below the base of the hand, and apply gentle pressure.
The pressure must be sufficient to feel the rhythmic throbbing of the arterial wall against the bone, but not so firm that it compresses the artery. If the pulse is not immediately felt, slightly adjust the position of the fingers or vary the pressure until the clearest pulsation is detected.
Measuring the Rate
Once the radial pulse is clearly felt, the next step is to accurately measure the rate, which is expressed in beats per minute (bpm). A watch with a second hand or a digital timer is necessary to establish the time interval for counting the beats. The most accurate method for determining the true heart rate, especially if the rhythm feels irregular, is to count the beats for a full 60 seconds.
For a quick assessment of a pulse that feels regular, the count can be taken over a shorter period to calculate the rate. A common method is to count the number of beats felt over 30 seconds and then multiply that number by two. Alternatively, counting for 15 seconds and multiplying by four can also provide a rapid estimate of the beats per minute.
To maintain accuracy, the counting should begin immediately upon feeling the first beat after the timer starts, often by counting the first pulse felt as “one.” If the pulse is found to be irregular, counting for the full 60 seconds is necessary to capture the variation and provide a more representative rate.
Interpreting Pulse Strength and Rhythm
The calculated heart rate for an adult at rest typically falls within a range of 60 to 100 beats per minute. A consistently lower resting rate, sometimes as low as 40 bpm in highly trained athletes, can indicate excellent cardiovascular fitness. Conversely, rates consistently above 100 bpm, or below 60 bpm in non-athletes, may warrant further consultation with a healthcare provider, especially if accompanied by symptoms like dizziness or shortness of breath.
Beyond the numerical rate, the strength of the pulse provides insight into the force of blood being pumped with each beat. A normal pulse is often described as strong or “expected,” meaning it is easily palpable with moderate pressure. A pulse that feels very forceful, or “bounding,” may be related to factors like exercise or stress, but can also be associated with fluid overload.
A pulse that is difficult to feel, described as “weak,” “thready,” or “diminished,” suggests a lower volume of blood being ejected by the heart. The rhythm is also assessed by noting the pattern of beats; a normal rhythm is regular, with equal intervals between each pulsation. An irregular rhythm, where beats are unevenly spaced, should be noted, as this can sometimes indicate an underlying cardiac arrhythmia that needs medical attention. Various factors, including medication, emotional state, and activity level, can temporarily influence both the rate and strength of the pulse.