Blood pressure is the force exerted by circulating blood against the walls of the arteries. This measurement is a fundamental indicator of cardiovascular health, reflecting how hard the heart must work to pump blood throughout the body. Many people seek a quick, non-device method, often attempting to use their fingers, to check this measurement. While fingers are excellent tools for sensing certain physiological signs, they cannot provide the detailed pressure values necessary for an accurate blood pressure reading.
The Limitation of Finger Measurement
Fingers can directly sense the rhythmic expansion and contraction of an artery, known as a pulse. This pulse is the pressure wave that travels through the vessels following each heartbeat, indicating the heart rate. Blood pressure, however, is composed of two distinct values: systolic pressure and diastolic pressure. Fingers cannot differentiate between these two pressures.
The systolic value reflects the maximum pressure during a heartbeat, while the diastolic value reflects the minimum pressure when the heart rests between beats. To accurately determine these two forces, it is necessary to temporarily stop the blood flow in the artery, a process called occlusion. Since a finger placed on the skin cannot achieve this mechanical occlusion, it is impossible to obtain a reliable blood pressure reading through palpation alone.
Checking Your Pulse Rate
Although measuring blood pressure with your fingers is not possible, you can use them to accurately measure your pulse rate and assess its characteristics. The most common site for this measurement is the radial artery, located on the thumb side of your wrist. Rest your arm on a flat surface with your palm facing upward and ensure you are relaxed.
Place the pads of your index and middle fingers—never your thumb—onto the groove just below the crease of your wrist, aligning them with the thumb side. Avoid using your thumb because it has its own strong pulse, which could lead to an inaccurate count. Apply light but firm pressure, just enough to clearly feel the throbbing sensation of the blood moving beneath your fingertips.
Once the pulse is located, use a watch or clock with a second hand to time your count. A common method for quickly determining heart rate is to count the number of beats over a 15-second period. Multiply that number by four to calculate the total beats per minute (BPM).
For a more precise reading, especially if the rhythm feels irregular, count the beats for a full 60 seconds. Pay attention to the pulse’s rhythm, noting if the beats are evenly spaced or erratic. You can also assess the strength, observing if the pulse feels strong and full or weak and thready.
Secondary locations, such as the carotid artery in the neck, can also be used, but the radial pulse is preferred for self-monitoring. A resting heart rate for a healthy adult typically falls between 60 and 100 BPM. Monitoring these characteristics provides valuable information about the heart’s function and rhythm.
Accurate Blood Pressure Measurement
Obtaining an accurate blood pressure measurement requires specialized instruments, such as an automatic monitor or a manual sphygmomanometer with a stethoscope. These devices operate on the principle of occlusion to capture the two distinct pressure points. The air-filled cuff is inflated around the upper arm until it temporarily stops the flow of blood through the main artery.
As the air is slowly released, the monitor senses the exact pressure at which blood first begins to push through the artery, which is the systolic pressure. It then records the pressure at which the blood flow becomes completely unrestricted, which is the diastolic pressure. Digital monitors achieve this by measuring pressure oscillations within the artery wall.
Health professionals recommend using a validated, cuff-style monitor on the upper arm for managing conditions like hypertension and ensuring accuracy for medical decisions. Devices worn on the wrist or finger are considered less reliable for regular monitoring because the arteries in those locations are narrower and positioned farther from the heart. Only a clinically approved device can provide the necessary precision for diagnosis and treatment adjustments.