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Definition: vital signs from Merriam-Webster's Collegiate(R) Dictionary

(1818) : signs of life; specif : the pulse rate, respiratory rate, body temperature, and often blood pressure of a person

Summary Article: Vital Signs
From The Gale Encyclopedia of Senior Health

Vital signs, which are also called simply vitals, are four measurements taken to determine whether a person is alive. The English word vital comes from the Latin vitalis, which means “pertaining to life” or “alive.” There are four standard vital signs: pulse (or heart) rate, breathing (or respiratory) rate, body temperature, and blood pressure.

Some healthcare professionals have suggested adding pain, evaluation of skin for color, and blood oxygen concentration to the basic list of vital signs, but these suggestions have not been accepted by most doctors.


A senior's vital signs may be taken for a number of reasons:

  • as part of a regular physical checkup

  • as part of a comprehensive geriatric assessment

  • to determine fitness for major surgery

  • as part of inpatient preparation for surgery and to monitor the senior's condition during and after the procedure

  • to help a medical professional diagnose possible cause(s) of a senior's symptoms (e.g., an irregular pulse in an elderly patient as well as the pattern of the irregularity can help a medical professional determine whether a senior has a heart condition that requires immediate attention or is perhaps of little importance)

  • to monitor the course of a disease or a chronic health condition

  • to evaluate the effectiveness of medications and the need to increase or decrease the dosage

  • to measure the effects of an exercise program or physical therapy

  • to monitor a patient's progress, often from minute to minute, during critical resuscitation

  • to determine time of death


The precautions to be observed by a health professional taking vital signs include care to avoid exposing the senior to infection (such as from soiled or contaminated equipment), and care in maintaining any equipment used to measure vital signs (to avoid inaccurate measurements).

Precautions that should be taken to ensure a senior's safety during a physical examination include:

  • Allow the senior extra time to undress, move to the examining table, and dress afterward. The table should be a comfortable height for the patient. Or, a medical professional can take vital signs with the patient seated in a chair.

  • As a safeguard against falls, frail seniors should not be left alone in an examining room.


The pulse should be taken in both arms in seniors. The reason for this precaution is that some heart or circulation problems result in a difference in volume in the blood flow on the two sides of the body, and a medical worker can sometimes feel this difference by taking the pulse on both sides at the same time. When a medical worker takes a senior's pulse, ideally he or she will be trying to evaluate the stiffness of the blood vessel wall as well as the rhythm and strength of the pulse, as stiffening of the blood vessels in the aging body is a common development.

The most common location for taking the pulse is the radial artery, which runs along the side of the wrist and can be felt just below the thumb. A medical worker may also take the pulse using the carotid artery just below the jaw, the femoral artery in the groin, or at the ankle or foot.


Breathing rate is measured by a medical worker's counting the number of breaths for a full minute and observing the pattern. Although most adults take between 12 and 18 breaths per minute, seniors in long-term care with respiratory problems may take 16–25 breaths per minute. If a senior is taking more than 20 breaths per minute, a medical worker will consider the possibility of an upper respiratory infection, congestive heart failure, lung disease, asthma, pneumonia, or other serious infection or stress on the body.

If a senior is taking 10 breaths or fewer per minute, a medical worker will consider the possibility of heavy drinking, overuse of benzodiazepine tranquilizers, or high doses of painkillers, as these substances depress the central nervous system. Another possible explanation for a low breathing rate is meningitis or other serious process altering brain function.


A person's temperature is taken with a thermometer. Glass thermometers that used to require placement for three minutes and posed a risk of breaking have been replaced in many settings by electronic thermometers that record temperature accurately within seconds. A medical worker should be careful to use a thermometer that will record temperatures below 95 F, as the major change in the aging body is not temperature level but the ability to regulate body temperature. It is also possible for a senior to have an infection without a noticeable fever. A temperature below 95°F in an elderly person should be rechecked because it may indicate acute illness or a severe medication reaction. Fever in a senior is usually defined as a temperature above 100°F.

In addition to taking a person's oral temperature, a medical worker may take the temperature again in the armpit or rectum. Seniors who breathe more rapidly than 20 breaths per minute may have artificially low oral temperatures. In some medical emergencies it may also be necessary to take the temperature in the armpit or rectum rather than the mouth.

Aging changes in vital signs

Adapted from A.D.A.M. Medical Encyclopedia, available at (© 2015 Cengage Learning)

Blood pressure

Blood pressure is measured by a device called a sphygmomanometer, which consists of an inflatable cuff to constrict blood flow, connected to a mercury tube or digital gauge to record the pressure. Measurements are expressed in millimeters of mercury (mm Hg). To take blood pressure, a medical worker places the cuff around the upper arm at the level of the heart, usually while the patient is sitting upright. The medical worker listens with a stethoscope at the inside of the senior's elbow and inflates the cuff until the brachial artery in the upper arm is squeezed shut. The medical worker then slowly releases the pressure in the cuff until a whooshing sound is heard as blood flow returns to the artery. The pressure in the cuff at which a sound first appears defines the systolic pressure (the highest level of blood pressure in the arteries). As the cuff is then further released, the artery will continue to make noise as long as the cuff somewhat restricts blood flow. Finally, the pressure in the cuff will drop below the diastolic pressure (the lowest level of blood pressure in the arteries), where all sounds from the artery disappear.

Blood pressure is usually taken in both arms in seniors for the same reason that the pulse is taken on both sides of the body—to screen for possible circulation disorders. In addition, a medical worker should try to estimate whether a high reading is an accurate measurement of blood pressure or whether it is caused by stiffening of the patient's blood vessels. This condition is called pseudohypertension.

Although not generally regarded as vital signs, a number of other measurements may also be taken along with those already mentioned. These additional measurements include a person's weight, height, and pulse oxygen. Pulse oxygen is a measure of the degree to which a person's blood is saturated with oxygen. A low level of oxygen in the blood may be an indication of hypoxemia, a deficiency of oxygen in the blood, which in turn may suggest a number of medical conditions including anemia, a blocked airway, congenital heart disease, or a variety of respiratory disorders. Pulse oxygen is generally determined with a device that is placed on a finger. The device transmits a light pulse through the finger and measures the wavelength of light absorbed. This measure provides an indication of oxygen saturation of the blood. Normal blood saturation levels are in the range of 95% to 99%.

A health worker may also calculate the body mass index (BMI) for a person from weight and height measurements. BMI is widely used for the determination of weight problems, such as overweight and obesity. BMI values between 18.5 and 24.9 are generally regarded as normal, while those between 25 and 29.9 are regarded as indicating a condition of overweight, and those 30 and over are defined as an indication of obesity. BMI values in excess of 35 are regarded as an indication of severe obesity, and values over 40 are defined as a condition of morbid obesity because a person with a BMI in this range is thought to be at risk of death from her or his weight.


There are few special preparations required for the taking of vital signs. The patient may be asked to roll up sleeves or remove a shirt or blouse if the measurements are taken as part of a routine office visit. Oral temperature should not be recorded immediately after the patient drinks a cold or hot liquid, and tympanic temperature should not be recorded immediately after the patient has been in cold air. Also, pulse, respiratory rate, or blood pressure measurements could be misleading if the patient has, say, just dashed into the office from the parking lot.


It is rare for serious complications to occur as the result of taking vital signs because these measurements do not involve drawing blood or other invasive procedures. Some elderly persons with very fragile skin, however, may notice bruising after the use of a blood pressure cuff.


Normal ranges for vital signs in healthy adults are as follows:

  • Temperature: between 97.8°F and 99.1 F. This range is the same in seniors as in younger adults.

  • Breathing rate: 12 to 18 breaths per minute. Changes in a senior's lungs do not always affect the rate of breathing; however, some seniors in long-term care with respiratory problems may have a breathing rate as high as 25 breaths per minute.

  • Pulse: Between 60 and 80 beats per minute when the person is at rest. In seniors, however, the pulse is often slightly slower than in younger adults. It takes longer for a senior's pulse to speed up during exercise and longer for it to slow down after exercise. In addition, the maximum heart rate with exercise is lower in seniors than in younger adults.

  • Blood pressure: systolic 120 mm Hg or less; diastolic 80 mm Hg or less. In seniors, however, blood pressure is often higher than normal values in younger adults; it may be as high as 150/90 mm Hg even when a senior is being treated for high blood pressure. It should be noted that the accepted cut-off points for normal blood pressure have changed somewhat over the years, and may change further.

Healthcare team roles

Taking vital signs is a routine medical procedure that does not require a special request. In most cases, a senior's vital signs will be taken by a physician, physician assistant, or registered nurse. Emergency responders, such as an emergency medical technician (EMT), paramedic, member of a rescue squad, firefighter, or police officer, may also check vital signs.

See also Aging; Blood pressure; Body mass index; Geriatric assessment tests; Health history; Hypertension; Hypotension; Postoperative care; Senior health.

  • Beaman, Nina, et al. Pearson's Comprehensive Medical Assisting: Administrative and Clinical Competencies. 3rd ed. Pearson Boston, 2015.
  • Zucker, Elana D. Being a Caregiver in a Home Setting. Pearson Boston, 2013.
  • Vaidehi, V., et al. “Agent Based Health Monitoring of Elderly People in Indoor Environments Using Wireless Sensor Networks.” Procedia Computer Science 19 (2013): 64-71.
  • Wang, Zhelong; Cong Zhao; Sen Qiu. “A System of Human Vital Signs Monitoring and Activity Recognition Based on Body Sensor Network.” Sensor Review 34, no. 1 (2014): 42-50.
  • MedlinePlus. “Vital Signs.” U.S. National Library of Medicine, National Institutes of Health. (accessed December 21, 2014).
  • University of Maryland Medical Center. “Aging Changes in Vital Signs.” (accessed December 21, 2014).
  • American Academy of Family Physicians (AAFP), 11400 Tomahawk Creek Parkway Leawood KS 66211, (913) 906-6000, (800) 274-2237, Fax: (913) 906-6269,
  • National Heart, Lung, and Blood Institute (NHLBI), PO Box 30105 Bethesda MD 20824, (301) 592-8573, Fax: (240) 629-3246,,
  • Rebecca J. Frey, PhD
    David E. Newton, EdD
    Kenneth Berniker, MD
    COPYRIGHT 2015 Gale, Cengage Learning

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