Vital Signs (Body Temperature, Pulse Rate, Respiration Rate, Blood Pressure)
What are vital signs?
Vital signs are measurements of the body's most basic functions. The 4 main vital
signs routinely monitored by healthcare providers include:
Breathing rate (respiration)
Blood pressure (Blood pressure is not considered a vital sign, but is often measured
along with the vital signs.)
Vital signs are useful in detecting or monitoring medical problems. Vital signs can
be measured in a medical setting, at home, at the site of a medical emergency, or
What is body temperature?
The normal body temperature of a person varies depending on gender, recent activity,
food and fluid consumption, time of day, and, in women, the stage of the menstrual
cycle. Normal body temperature can range from 97.8° F (36.5°C) to 99°F (37.2°C) for
a healthy adult. A person's body temperature can be taken in any of the following
Orally. Temperature can be taken by mouth using either the classic glass thermometer, or the
more modern digital thermometers that use an electronic probe to measure body temperature.
Rectally. Temperatures taken rectally (using a glass or digital thermometer) tend to be 0.5°F
to 0.7°F higher than when taken by mouth.
Armpit (axillary). Temperatures can be taken under the arm using a glass or digital thermometer. Temperatures
taken by this route tend to be 0.3°F to 0.4°F lower than those temperatures taken
By ear. A special thermometer can quickly measure the temperature of the eardrum, which reflects
the body's core temperature (the temperature of the internal organs).
By skin. A special thermometer can quickly measure the temperature of the skin on the forehead.
Body temperature may be abnormal due to fever (high temperature) or hypothermia (low
temperature). A fever is indicated when body temperature rises about one degree or
more over the normal temperature of 98.6°F, according to the American Academy of Family
Physicians. Hypothermia is defined as a drop in body temperature below 95°F.
Glass thermometers containing mercury
According to the Environmental Protection Agency (EPA), mercury is toxic and poses
a threat to the health of humans, as well as to the environment. Because of the risk
of breaking, glass thermometers with mercury should be not be used. If you have a
mercury thermometer, dispose of it properly in accordance with local, state, and federal
laws. Contact your local health department, waste disposal authority, or fire department
for information on how to properly dispose of mercury thermometers.
What is the pulse rate?
The pulse rate is a measurement of the heart rate, or the number of times the heart
beats per minute. As the heart pushes blood through the arteries, the arteries expand
and contract with the flow of the blood. Taking a pulse not only measures the heart
rate, but also can indicate the following:
Strength of the pulse
The normal pulse for healthy adults ranges from 60 to 100 beats per minute. The pulse
rate may fluctuate and increase with exercise, illness, injury, and emotions. Females
ages 12 and older, in general, tend to have faster heart rates than do males. Athletes,
such as runners, who do a lot of cardiovascular conditioning, may have heart rates
near 40 beats per minute and experience no problems.
How to check your pulse
As the heart forces blood through the arteries, you feel the beats by firmly pressing
on the arteries, which are located close to the surface of the skin at certain points
of the body. The pulse can be found on the side of the neck, on the inside of the
elbow, at the wrist, or in the groin. For most people, it is easiest to take the pulse
at the wrist. If you use the lower neck, be sure not to press too hard, and never
press on the pulses on both sides of the lower neck at the same time to prevent blocking
blood flow to the brain.
When taking your pulse:
Using the first and second fingertips, press firmly but gently on the arteries until
you feel a pulse.
Begin counting the pulse when the clock's second hand is on the 12.
Count your pulse for 60 seconds (or for 15 seconds and then multiply by 4 to calculate
beats per minute).
When counting, do not watch the clock continuously, but concentrate on the beats of
If unsure about your results, ask another person to count for you.
If your doctor has ordered you to check your own pulse and you are having trouble
finding it, consult your doctor or nurse for additional instruction.
What is the respiration rate?
The respiration rate is the number of breaths a person takes per minute. The rate
is usually measured when a person is at rest and simply involves counting the number
of breaths for one minute by counting how many times the chest rises. Respiration
rates may increase with fever, illness, and with other medical conditions. When checking
respiration, it is important to also note whether a person has any trouble breathing.
Normal respiration rates for an adult person at rest range from 12 to 16 breaths per
What is blood pressure?
Blood pressure is the force of the blood pushing against the artery walls during contraction
and relaxation of the heart. Each time the heart beats, it pumps blood into the arteries,
resulting in the highest blood pressure as the heart contracts. When the heart relaxes,
the blood pressure falls.
Two numbers are recorded when measuring blood pressure. The higher number, or systolic
pressure, refers to the pressure inside the artery when the heart contracts and pumps
blood through the body. The lower number, or diastolic pressure, refers to the pressure
inside the artery when the heart is at rest and is filling with blood. Both the systolic
and diastolic pressures are recorded as "mm Hg" (millimeters of mercury). This recording
represents how high the mercury column in an old-fashioned manual blood pressure device
(called a mercury manometer or sphygmomanometer) is raised by the pressure of the
blood. Today, your doctor's office is more likely to use a simple dial for this measurement.
High blood pressure, or hypertension, directly increases the risk of heart attack,
heart failure, and stroke. With high blood pressure, the arteries may have an increased
resistance against the flow of blood, causing the heart to pump harder to circulate
Blood pressure is categorized as normal, elevated, or stage 1 or stage 2 high blood
Normal blood pressure is systolic of less than 120 and diastolic of less than 80 (120/80)
Elevated blood pressure is systolic of 120 to 129 and diastolic less than 80
Stage 1 high blood pressure is systolic is 130 to 139 or diastolic between 80 to 89
Stage 2 high blood pressure is when systolic is 140 or higher or the diastolic is 90 or higher
These numbers should be used as a guide only. A single blood pressure measurement
that is higher than normal is not necessarily an indication of a problem. Your doctor
will want to see multiple blood pressure measurements over several days or weeks before
making a diagnosis of high blood pressure and starting treatment. Ask your provider
when to contact him or her if your blood pressure readings are not within normal range.
Why should I monitor my blood pressure at home?
For people with high blood pressure, home monitoring allows your doctor to monitor
how much your blood pressure changes during the day, and from day to day. This may
also help your healthcare provider determine how effectively your blood pressure medicine
What special equipment is needed to measure blood pressure?
You can use either an aneroid monitor, which has a dial gauge and is read by looking
at a pointer, or a digital monitor, in which the blood pressure reading flashes on
a small screen.
The aneroid monitor is less expensive than the digital monitor. The cuff is inflated
by hand by squeezing a rubber bulb. Some units even have a special feature to make
it easier to put the cuff on with one hand. However, the unit can be easily damaged
and become less accurate. Because the person using it must listen for heartbeats with
the stethoscope, and master the proper technique required for an accurate measurement,
it may not be as useful. It also may not be appropriate for the hearing-impaired or
for single person use.
The digital monitor is automatic, with the measurements appearing on a small screen.
Because the recordings are easy to read, this is the most popular blood pressure measuring
device. It is also easier to use than the aneroid unit, and since there is no need
to listen to heartbeats through the stethoscope, this is a good device for hearing-impaired
patients. One disadvantage is that body movements or an irregular heart rate can change
the accuracy. These units are also more expensive than the aneroid monitors.
Finger and wrist blood pressure monitors
Tests have shown that finger and/or wrist blood pressure devices are not as accurate
in measuring blood pressure as other types of monitors. They are also more expensive
than the other monitors.
Before you measure your blood pressure
The American Heart Association recommends the following guidelines for home blood
Don't smoke or drink coffee for 30 minutes before taking your blood pressure.
Go to the bathroom before the test.
Relax for 5 minutes before taking the measurement.
Sit with your back supported (don't sit on a couch or soft chair). Keep your feet
on the floor uncrossed. Place your arm on a solid flat surface (like a table) with
the upper part of the arm at heart level. Place the middle of the cuff directly above
the bend of the elbow. Check the monitor's instruction manual for an illustration.
Take multiple readings. When you measure, take 2 to 3 readings one minute apart and
record all the results.
Take your blood pressure at the same time every day, or as your healthcare provider
Record the date, time, and blood pressure reading.
Take the record with you to your next medical appointment. If your blood pressure
monitor has a built-in memory, simply take the monitor with you to your next appointment.
Call your provider if you have several high readings. Don't be frightened by a single
high blood pressure reading, but if you get several high readings, check in with your
When blood pressure reaches a systolic (top number) of 180 or higher OR diastolic
(bottom number) of 110 or higher, seek emergency medical treatment.
Ask your doctor or another healthcare professional to teach you how to use your blood
pressure monitor correctly. Have the monitor routinely checked for accuracy by taking
it with you to your doctor's office. It is also important to make sure the tubing
is not twisted when you store it and keep it away from heat to prevent cracks and
Proper use of your blood pressure monitor will help you and your doctor in monitoring
your blood pressure.