University of Iowa Health Science Relations and
Hans House, MD
Assistant Professor of Emergency Medicine
First Published: 2000
Last Revised: October 2004
Peer Review Status: Internally Peer Reviewed
If you have ever watched a TV medical show or had a physical examination, no doubt you've heard the term "vital signs." But do you know what it means?
Your vital signs are body temperature, blood pressure and heart and respiration rates. They are indications of your health.
Although 98.6 degrees Fahrenheit has long been called the normal body temperature, a degree either side of that is fine, says Dr. Hans House, an emergency medicine physician at University of Iowa Hospitals and Clinics. He says many things can affect your temperature. For example, body temperature drops in the early morning during sleep as a normal body rhythm. And, strenuous exercise can raise your temperature to 100 degrees Fahrenheit. Any measurement higher than that is considered not normal, he adds.
Blood pressure is normally taken with a device that has an inflatable cuff that is wrapped around the upper arm. The instrument measures the force of the blood against the artery walls and is expressed by two numbers. The first number is the pressure when the heart is beating, the second number is the pressure between heart beats. Dr. House says 120/80 or 120/70 is average.
"The second number is important. If you think of the heart as a pump, and the second number is the resistance against which the pump works, you can see that the higher that number, the harder the pump has to work," he says.
Heart rate, or pulse, is the rate at which your heart pumps blood through your body. For an adult the average is 70 to 72 beats per minute, but this can vary a little in either direction and still be normal, Dr. House says. In children and infants the heart rate is normally higher. Well-conditioned athletes can have heart rates as low as 40, he says.
Respiration, or breathing rate, is how many breaths you take in a minute. It can be influenced by exercise, apprehension or other factors. The average rate for an adult is 14 to 18 breaths, and also is normally higher for children and infants.