Vital Signs

History and Physical

Most physical exams will begin with the patient being asked questions about their medical history and current situation including any problems or medications they are on.

Vital signs

Temperature

Temperature recording gives an indication of core body temperature which is normally tightly controlled (thermoregulation) as it affects the rate of chemical reactions.

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). 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. Temperature can be measured by: ear, axillary, oral, or rectal (most accurate although rarely done).

Blood Pressure

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. Usually the blood pressure is taken in the right 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. Elevated blood pressure hypertension therefore 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 are called segmental blood pressures and are used to evaluate blockage or arterial occlusion in a limb (see Ankle brachial pressure index).

Pulse

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 is taken is 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 90-110 beats per minute, adolescents around 80-100 beats per minute, and adults pulse rate is anywhere between 50 and 80 beats per minute.

Respiratory rate

Varies with age, but the normal reference range is 16-20 breaths/minute.

Basic Biometrics

Height

Height is the anthropometric longitudinal growth of an individual. A statiometer is the device used to measure height although often a height stick is more frequently used for vertical measurement of adults or children older than 2. The patient is asked to stand barefoot. Height declines during the day because of compression of the intervertebral discs. Children under age 2 are measured lying horizontally.

Weight

Weight is the anthropometric mass of an individual. A scale is used to measure weight.

Body mass index, or BMI, is used to calculate the relationship between healthy height and weight and obesity or being overweight or underweight.

Medical professionals generally prefer to use the SI unit of kilograms, and many medical facilities have ready-reckoner conversion charts available for professionals to use, when patients describe their weight in non-SI units. (In the US, pounds and ounces are common, while in the UK stones and pounds are frequently used; in most other countries the metric system predominates.)

Pain

Because of the importance of pain to the overall wellness of the patient, subjective measurement is considered to be a vital sign. Clinically pain is measured using a FACES scale which is a series of faces from '0' (no pain at all showing a normal happy face) to '5' (the worst pain ever experienced by the patient). There is also an analog scale from '0' to maximum '10'. It is important to allow patients to make their own choices on a pain scale. Physicians and health care workers frequently understate patient pain.