How can doctors tell our temperature by feeling our pulse?

There is a connection between the rate at which our pulse beats and the temperature of our body. They go more or less together. So, when the doctor counts pulse rate and finds that it is just the rate it should be, he also expects to find the temperature quite usual. If however, he finds that the pulse is twice as rapid as usual, he will also probably find that the temperature is much higher than normal. This is because the thing that causes the pulse to become rapid causes the temperature to go up.

Thus, in all cases of fever where there is some poisonous substance in the body, it causes the heart to beat faster, and the pulse to become rapid. Also, it causes a disturbance in that part of the brain controlling the temperature, so that both the pulse and the temperature are thrown out of gear.

The Body Temperature

The normal range of human body temperature is from 98° Fahrenheit to 99° Fahrenheit. Fever or pyrexia occurs in a bid to wipe out any infection that our body might have contracted. The body’s immune system sends its ‘soldiers’, the white blood cells to counteract the infectious agents. The chemicals released in the process cause the body temperature to rise. Simultaneously, these chemicals increase the activity of the heart to provide adequate nutrition to the agents. 

Why Does The Heart Beat Faster?

During an infection, the heart rate increases to pump sufficient blood and hence nutrition to the white blood cells fighting the infection, or poison or toxin, the heart must start pumping more blood. Thus, causing the heart rate and even the respiratory rate to rise. The beating of the heart can be felt as pulse throughout the designated locations on our body. Therefore, an increased rate of the beating of the heart, or pulse is indicative of fever.

Naturally, your heart beats faster after activity, in excitement or fear, etc. But an increased pulse rate at rest is often indicative of fever. Thus the doctor simply has to measure the pulses rate at rest to find out if you have a fever. 

The Numeric Relation between Pulse and Temperature

The normal pulse rate of a human depends on age and gender. Males have a naturally faster pulse than women, and children’s pulse rates are also much higher. A doctor who knows the normal values can predict your approximate temperature just by feeling your pulse. Studies have shown that for every 1-degree rise in body temperature, the heart rate increases by ten beats per minute. So, a heart of 90 instead of 70 beats per minute is indicative of a fever of 100-degree Fahrenheit.

However, a pulse rate of 72 beats is not fixed for everybody. Each one of us must keep a record of their pulse rate, and note down any variations that may occur.