Vital signs measure the body’s most essential functions. They include heart rate, body temperature, respiratory rate, blood pressure, and oxygen saturation.

Healthcare professionals use vital signs to quickly assess a person’s overall health status. Vital signs are measurable factors that show how a person’s heart is working, how their lungs are functioning, and how severely their body is responding to infection or injury.

Regularly monitoring vital signs helps healthcare professionals establish what typical function looks like for an individual. Over time, this can help them understand improvements in the person’s health or spot potentially negative trends in important bodily processes with few measurements.

This article further explains vital signs. It lists and discusses each vital sign and goes over what normal levels are.

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Vital signs are measurable signs of life and overall health status. They are the first step healthcare professionals take when checking a person for a medical problem.

Healthcare professionals use vital signs to work out how far a person’s health has deviated from normal, healthy ranges. Vital signs can help them determine which individuals require emergency assistance and which they can refer for less urgent treatment.

The traditional definition of vital signs includes:

  • heart rate
  • body temperature
  • respiratory rate
  • blood pressure

However, according to a 2023 paper, since the COVID-19 pandemic, some medical schools of thought recommend including oxygen saturation as the fifth vital sign.

According to the American Heart Association (AHA), heart rate is the number of times the heart beats in 1 minute.

When the heart beats, it causes major blood vessels throughout the body to expand and contract. This is known as the pulse, which allows a person to feel and assess their heartbeat.

Changes in heart rate can highlight heart problems, medication side effects, or high levels of exertion. Certain factors can alter heart rate, including:

  • high air temperature
  • intense emotions
  • standing up
  • certain medications

Severe obesity may also lead to a higher resting heart rate.

Resting heart rate refers to the number of beats per minute (bpm) while sitting or lying down in a relaxed state.

A normal resting heart rate is between 60 and 100 bpm.

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However, highly active people may have a normal resting heart rate as low as 40 bpm due to a healthier heart that does not need to work as hard to pump blood.

Learn more about heart rate.

How to measure pulse

People can find their pulse in the following locations:

  • side of the neck
  • wrists
  • inside of the elbow
  • top of the foot

To calculate a pulse, place a finger over a pulse point and count the number of beats that occur in a 60-second window. Most people outside of the healthcare profession measure the pulse on a wrist.

Some people may use wearable fitness trackers, such as smartwatches, to monitor their heart rate.

A 2022 study with 201 people using trackers found that they may be inaccurate by around 5 bpm on average when compared with an electrocardiogram, the most accurate measurement of heart rate.

Learn more about how to check the pulse.

Body temperature refers to how hot or cool a person’s internal, or “core,” temperature is. Normal bodily processes, including sleep, hormone changes, and activity, naturally cause body temperature to vary slightly throughout the day.

A normal body temperature is 98.6°F (37°C).

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Several types of thermometers can accurately detect body temperature, including:

  • a digital sublingual thermometer, which goes under the tongue
  • a digital rectal thermometer, which is inserted into the rectum
  • infrared thermometers, which do not require contact with the skin

Learn more about the types of thermometers available.


An increased body temperature, or fever, may suggest the presence of:

  • an infection
  • an illness
  • an autoimmune problem
  • cancer

Different categories of fever can point to different disease severities. Healthcare professionals often divide fevers into three categories:

  • Low grade: 99.1°F to 100.4°F (37.3°C to 38°C)
  • Moderate grade: 100.6°F to 102.2°F (38.1°C to 39°C)
  • High grade: 102.4°F to 105.8°F (39.1°C to 41°C)

Hyperthermia occurs when the body temperature is higher than 105.8°F (41°C). This differs from fever in important ways.

Hyperthermia occurs when the environment is too hot and the body’s usual heat control methods, such as sweating, are not helping the body cool down. This can lead to conditions including heatstroke and requires immediate medical attention.

Learn more about body temperature.

Respiratory rate is the number of breaths a person takes per minute. This differs between people and decreases with age.

A normal respiratory rate ranges from 12 to 20 breaths per minute.

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While faster breathing can indicate normal physical exertion, a faster respiratory rate than normal can point to several health problems, including:

Slower-than-normal breathing may point to different health risks, such as:

Learn more about respiratory rate.

Blood pressure refers to the force of blood pushing against the walls of blood vessels while it moves around the body.

The unit for blood pressure is millimeters of mercury (mm Hg). Blood pressure readings occur as two figures. They list systolic pressure, which is the force of the heart expanding, over diastolic pressure, which measures pressure as the heart rests between beats.

Systolic blood pressure is the top number. Diastolic blood pressure is the bottom number.

Normal blood pressure is less than 120/80 mm Hg.

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Learn more about blood pressure readings.

High blood pressure

Consistently high blood pressure means the heart is working harder than usual. High blood pressure increases the risk of:

Often, high blood pressure does not cause symptoms. This means healthcare professionals may recommend regular monitoring if they believe someone is at risk of high blood pressure.

Learn more about high blood pressure.

Oxygen saturation compares how much oxygen has bound to hemoglobin in the blood with how much has not. The hemoglobin in red blood cells transports oxygen around the body, so this can show how much oxygen tissues can use to function well.

Oxygen saturation can help a healthcare professional identify lung disease and life threatening events involving low oxygen.

Healthcare professionals often consider oxygen saturation to be the fifth vital sign.

They may measure oxygen saturation as part of screening and assessment for respiratory diseases, such as COVID-19 or chronic obstructive pulmonary disease (COPD).

A normal oxygen saturation is between 95% and 100%.

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According to the U.K. National Health Service (NHS), people with 93% to 94% oxygen saturation should consult a healthcare professional, and people with 92% or less require emergency assistance.

People with existing lung problems may have lower oxygen saturation without necessarily needing a non-routine consultation.

Learn about pulse oximetry.

Normal vital signs in adults stay relatively consistent. Vital signs vary more in children as they approach adulthood.


This table lists the normal vital signs for adults ages 18 years and older.

Vital signNormal range
Heart rate60 to 100 beats per minute
Body temperature98.6°F (37°C)
Oxygen saturation95% to 100%
Respiratory rate12 to 20 breaths per minute
Blood pressure120/80 mm Hg


Normal vital sign ranges may vary based on a child’s size and sex. Some normal ranges for vital signs, such as oxygen saturation and body temperature, are the same at any age.

Vital signInfant (0 to 12 months)Child (1 to 11 years)Teenager (12 years and up)
Heart rate100 to 180 bpm? 1 to 2 years: 98 to 140 bpm
? 3 to 5 years: 80 to 120 bpm
? 6 to 11 years: 75 to 118 bpm
60 to 100 bpm
Body temperature98.6°F (37°C)98.6° F (37° C)98.6° F (37° C)
Oxygen saturation95% to 100%95% to 100%95% to 100%
Respiratory rate30 to 60 breaths per minute? 1 to 3 years: 24 to 40 breaths per minute
? 3 to 6 years: 22 to 34 breaths per minute
? 6 to 12 years: 18 to 30 breaths per minute
12 to 16 breaths per minute
Blood pressureNewborn weighing less than 1 kilogram (kg):
? 39 to 59 systolic
? 16 to 36 diastolic
Newborn weighing more than 1 kg:
? 60 to 76 systolic
? 31 to 45 diastolic
First month:
? 72 to 104 systolic
? 37 to 56 diastolic
1 to 12 months:
? 67 to 84 systolic
? 35 to 53 diastolic
1 to 2 years:
? 86 to 106 systolic
? 42 to 63 dialostic
3 to 5 years:
? 89 to 112 systolic
? 46 to 72 diastolic
6 to 9 years:
? 97 to 115 systolic
? 57 to 76 diastolic
10 to 11 years:
? 102 to 120 systolic
? 61 to 80 diastolic
? 110 to 131 systolic
? 64 to 83 diastolic

Vital signs are measurable values that indicate a person’s overall state of health. They include heart rate, blood pressure, respiratory rate, body temperature, and oxygen saturation. People can measure vital signs at home, or a medical professional can assess them in a clinical setting.

Regularly checking these values can help healthcare professionals identify underlying health problems and reduce the risk of future complications.

Vital signs can also indicate when emergency care is necessary to restore signs to normal ranges. Adults and children have different normal ranges for most vital signs.