What are vital signs?
Vital signs are used to measure the body's basic functions. These measurements are taken to help assess the general physical health of a person, give clues to possible diseases and show progress toward recovery. The normal ranges for a person's vital signs vary with age, weight, gender and overall health.
There are four main vital signs: body temperature, blood pressure, pulse (heart rate), and breathing rate.
Body temperature: The average body temperature is 98.6º Fahrenheit, but normal temperature for a healthy person can range between 97.8º to 99.1º Fahrenheit or slightly higher. Body temperature is measured using a thermometer inserted into the mouth, anus, or placed under the armpit. Body temperature can also be measured by a special thermometer inserted into the ear canal. Any temperature that is higher than a person's average body temperature is considered a fever. A drop in body temperature below 95º Fahrenheit is defined as hypothermia. Keep in mind that temperature can vary due to factors other than illness or infection. Stress, dehydration, exercise, being in a hot or cold environment, drinking a hot or cold beverage and thyroid disorders can influence body temperature. Because older adults do not control body temperature as well as younger adults, older adults may be ill without ever displaying signs of a fever.
Blood pressure: Blood pressure is the measurement of the pressure or force of blood against the walls of your arteries. Blood pressure is written as two numbers, such as 120/80 millimeters of mercury (mm Hg). The first number is called the systolic pressure and measures the pressure in the arteries when the heart beats and pushes blood out to the body. The second number is called the diastolic pressure and measures the pressure in the arteries when the heart rests between beats.
Healthy blood pressure for an adult, relaxed at rest, is considered to be a reading less than 120/80 mm Hg. A systolic pressure of 120-139 or a diastolic pressure of 80-89 is considered "prehypertension" and should be closely monitored. Hypertension (high blood pressure) is considered to be a reading of 140/90 mm Hg or higher. Blood pressure that remains high for an extended period of time can result in such health problems as atherosclerosis (hardening of the arteries), heart failure and stroke.
Some factors that can influence a blood pressure reading include:
- Cold temperatures
- Full stomach
- Full bladder
- Caffeine, alcohol consumption
- Certain medicines
- Gaining or losing weight
- Salt intake
If you are taking your blood pressure, beware of these factors when reading your measurements. If someone else is taking your blood pressure, be sure to tell him or her of any these possible causes you may have for high blood pressure. Also know that the blood pressure stations at some drug stores and grocery stores are not considered accurate measures of your blood pressure. Hypotension (low blood pressure) is a reading of 90/60 mm Hg or lower, which can be normal for some people and not a cause for concern. However, if your low blood pressure causes signs or symptoms such as dizziness, fainting, nausea, cold sweats and blurred vision, talk to your doctor to discover if another condition or illness is behind the problem.
Pulse: Your pulse is the number of times your heart beats per minute. Pulse rates vary from person to person. Your pulse is lower when you are at rest and increases when you exercise (because more oxygen-rich blood is needed by the body when you exercise). A normal pulse rate for a healthy adult at rest ranges from 60 to 80 beats per minute. Women tend to have faster pulse rates than men. Your pulse can be measured by firmly but gently pressing the first and second fingertips against certain points on the body — most commonly at the wrist or neck (but can also be measured at the bend of the arms, in the groin, behind the knees, inside the ankles, on the top of the feet or at the temple area of the face) — then counting the number of heart beats over a period of 60 seconds. A faster than average pulse can indicate such health problems as infection, dehydration, stress, anxiety, a thyroid disorder, shock, anemia or certain heart conditions. Some medications, especially beta blockers and digoxin, can slow your pulse. A lower heart rate is also common for people who get a lot of exercise or are athletic. If checking your pulse, your pulse rate should not be routinely less than 60 beats per minute. The beats also should be equally spaced out, not excessively strong (would indicate a heart that is working hard), and no beats should be missed.
Respiratory rate: A person's respiratory rate is the number of breaths you take per minute. The normal respiration rate for an adult at rest is 12 to 20 breaths per minute. A respiration rate under 12 or over 25 breaths per minute while resting is considered abnormal. Among the conditions that can change a normal respiratory rate are asthma, anxiety, pneumonia, congestive heart failure, lung disease, use of narcotics or drug overdose.