There are four vital signs which are standard in most medical settings:
Pulse rate (or heart rate)
The equipment needed is a thermometer, a sphygmomanometer, and a watch.
Though a pulse can often be taken by hand, a stethoscope may be required for a
patient with a very weak pulse.
Temperature recording gives an indication of core body temperature which is
normally tightly controlled (thermoregulation) as it affects the rate of
Temperature can be recorded in order to establish a baseline for the
individual's normal body temperature for the site and measuring conditions. The
main reason for checking body temperature is to solicit any signs of systemic
infection or inflammation in the presence of a fever (temp > 38.5 °C or
sustained temp > 38 °C), or elevated significantly above the individual's normal
temperature. Other causes of elevated temperature include hyperthermia.
Temperature depression (hypothermia) also needs to be evaluated. It is also
noteworthy to review the trend of the patient's temperature. A patient with a
fever of 38 °C does not necessarily indicate an ominous sign if his previous
temperature has been higher. Body temperature is maintained through a balance of
the heat produced by the body and the heat lost from the body.
determine whether a fever is present, an accurate body temperature is needed.
Medical research has not determined an exact correlation between oral, rectal,
ear (tympanic), and armpit (axillary) temperature measurements. Generally, the
correlation of temperature results are as follows:
The average normal oral temperature is 98.6°F (37°C). An oral temperature is
0.5°F (0.3°C) to 1°F (0.6°C) lower than a rectal or ear (tympanic) temperature.
A rectal temperature is 0.5°F (0.3°C) to 1°F (0.6°C) higher than an oral
An ear (tympanic) temperature is 0.5°F (0.3°C) to 1°F (0.6°C) higher than an
An armpit (axillary) temperature is usually 0.5°F (0.3°C) to 1°F (0.6°C) lower
than an oral temperature.
It is important to remember:
Rectal temperatures are generally thought to be the most accurate for checking a
The manufacturer of the temperature device you use, such as a tympanic
thermometer, provides information on how to use it. Be sure to read and follow
the instructions to obtain an accurate temperature. The information may also
include how the results of the device correlate with the results from other
methods of taking a temperature.
Plastic strip thermometers have some uses, but they are not recommended for
general home use. Unlike oral, rectal, and ear thermometers, plastic strip
thermometers measure skin temperature, not body temperature.
When you talk with your doctor about your temperature, be sure to say what
method was used to take the temperature.
Temperature is commonly considered to be a vital sign most notably in a hospital
setting. EMTs (Emergency Medical Technicians), in particular, are taught to
measure the vital signs of: respiration, pulse, skin, pupils, and blood pressure
as "the 5 vital signs" in a non-hospital setting.
The blood pressure is recorded as two readings; a high systolic pressure, which
is the maximal contraction of the heart, and the lower diastolic or resting
pressure. A normal blood pressure would be 120 being the systolic over 80, the
diastolic. Usually the blood pressure is read from the left arm unless there is
some damage to the arm. The difference between the systolic and diastolic
pressure is called the pulse pressure. The measurement of these pressures is now
usually done with an aneroid or electronic sphygmomanometer. The classic
measurement device is a mercury sphygmomanometer, using a column of mercury
measured off in millimeters. In the United States and UK, the common form is
millimeters of mercury, whilst elsewhere SI units of pressure are used. There is
no natural 'normal' value for blood pressure, but rather a range of values that
on increasing are associated with increased risks. The guideline acceptable
reading also takes into account other co-factors for disease. Therefore,
elevated blood pressure (hypertension) is variously defined when the systolic
number is persistently over 140–160 mmHg. Low blood pressure is hypotension.
Blood pressures are also taken at other portions of the extremities. These
pressures is called segmental blood pressures and are used to evaluate blockage
or arterial occlusion in a limb (see Ankle brachial pressure index).
The pulse is the physical expansion of the artery. Its rate is usually measured
either at the wrist or the ankle and is recorded as beats per minute. The pulse
commonly taken is from the radial artery at the wrist. Sometimes the pulse
cannot be taken at the wrist and is taken at the elbow (brachial artery), at the
neck against the carotid artery (carotid pulse), behind the knee (popliteal
artery), or in the foot dorsalis pedis or posterior tibial arteries. The pulse
rate can also be measured by listening directly to the heartbeat using a
stethoscope. The pulse varies with age. A newborn or infant can have a heart
rate of about 130–150 beats per minute. A toddler's heart will beat about
100–120 times per minute, an older child's heartbeat is around 60–100 beats per
minute, adolescents around 80–100 beats per minute, and adults' pulse rate is
anywhere between 50 and 80 beats per minute.
Varies with age, but the normal reference range for an adult is 12–20 breaths/minute.[citation
needed] The value of respiratory rate as an indicator of potential respiratory
dysfunction has been investigated but findings suggest it is of limited value.
Respiratory rate is clear indicator of acidotic states, as the main function of
respiration is removal of CO2 leaving bicarbonate base in circulation.