Vital signs are measurements of the body’s most basic functions. They include temperature, pulse, respiratory rate, blood pressure, and oxygen saturation.
Medical professionals use vital signs to get a general sense of a patient’s overall condition. They help detect and monitor medical problems and can be a warning sign of a serious illness.
In this article, we’ll take a closer look at each of the different types of vital signs and what they can tell us about our health.
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Primary Vital Signs
There are five primary vital signs that are recognized in the healthcare setting:
- Heart rate
- Respiratory rate
- Blood pressure
- Body Temperature
- Oxygen saturation
The primary vital signs can be measured objectively. That is, their values can be obtained without the need for interpretation by the patient.
For example, heart rate can be measured by feeling the pulse or by using an electrocardiogram (ECG). Respiratory rate can be measured by counting the number of breaths per minute.
Blood pressure can be measured using a sphygmomanometer or an automated blood pressure machine. Body temperature can be measured using a thermometer. And oxygen saturation can be measured using a pulse oximeter.
Heart rate, or pulse, is the number of times your heart beats per minute. A normal heart rate is 60–100 beats/min.
Heart rate can increase due to physical activity, anxiety, stress, fever, or certain medications. It can decrease due to hypothermia, hypotension, and shock.
An abnormal heart rate can be a sign of a number of medical conditions, such as arrhythmias, heart failure, and myocardial infarctions.
Respiratory rate is the number of breaths you take per minute. A normal respiratory rate is 12–20 breaths/min.
Respiratory rate can increase due to exercise, anxiety, infections, and some medical conditions (e.g., COPD, asthma). It can decrease due to head injuries and some medications (e.g., opioids).
An abnormal respiratory rate can be a sign of a number of medical conditions, such as pneumonia, heart failure, and other cardiopulmonary conditions.
Blood pressure is a measurement of the force of blood pushing against the walls of your arteries. Two readings are recorded:
- Systolic blood pressure (the top number) is the pressure when your heart beats and pumps blood out to the rest of your body.
- Diastolic blood pressure (the bottom number) is the pressure when your heart rests between beats.
The normal range for blood pressure is 120/80 mmHg.
Blood pressure can increase due to exercise, anxiety, and some medical conditions (e.g., heart failure, aortic stenosis). It can decrease due to head injuries, hypovolemia, and some medications (e.g., beta blockers).
An abnormal blood pressure can be a sign of a number of medical conditions, such as hypertension, hypotension, and shock.
Body temperature is a measurement of the body’s heat production and loss. The normal range for body temperature is 36–37.5°C (96.5–99.5°F).
Body temperature can increase due to exercise, fever, and some medical conditions (e.g., hyperthyroidism). It can decrease due to hypothermia, head injuries, and some medications (e.g., antipyretics).
An abnormal body temperature can be a sign of a number of medical conditions, such as infections, heat stroke, and cold exposure.
Oxygen saturation is a measurement of the concentration of oxygen that is bound to hemoglobin in arterial blood. The normal range for oxygen saturation is 93–100%.
Oxygen saturation can decrease due to hypoventilation, lung disease, and some medical conditions (e.g., anemia). It can increase as a result of receiving supplemental oxygen.
Hypoxemia is an abnormally low concentration of oxygen in the blood and can be a sign of several medical conditions, such as pneumonia, heart failure, and COPD.
Normal Vital Signs: Adults
|Heart rate||60–100 beats/min|
|Respiratory rate||12–20 breaths/min|
|Blood pressure||120/80 mmHg|
|Body temperature||98.6˚F (37˚C)|
|Oxygen saturation||> 93%|
Normal Vital Signs: Infant
|Heart rate||110–160 beats/min|
|Respiratory rate||30–60 breaths/min|
|Blood pressure||60/40 mmHg|
|Body temperature||98.6˚F (37˚C)|
|Oxygen saturation||> 90%|
|Blood glucose||> 30 mg/dL|
|Gestation age||40 weeks|
|Birth weight||≥ 3,000 grams|
|L/S ratio||≥ 2:1|
|Silverman Anderson Score||0–1|
Secondary Vital Signs
In addition to the vital signs described above, there are a number of other measurements that can be considered vital signs in certain situations.
These secondary vital signs include:
- Level of consciousness
- Blood glucose
- Skin color
- Pupillary assessment
Pain is a subjective measurement of discomfort that can vary depending on the individual patient.
It is often measured using a pain scale, which is a numerical rating system of 0–10 that allows patients to communicate the level of their pain to their healthcare providers.
Level of Consciousness
The level of consciousness is a measurement of a person’s responsiveness to their environment.
It can be measured using the Glasgow Coma Scale, which is a score of 3–15 that is based on a person’s ability to open their eyes, follow commands, and speak.
Blood glucose is a measurement of the concentration of sugar (glucose) in the blood. It is typically measured using a fingerstick blood test or a continuous glucose monitor.
The normal range for blood glucose is 70–139 mg/dL.
Hyperglycemia is a condition in which the blood sugar levels are abnormally high and can be a sign of diabetes.
Hypoglycemia is a condition in which the blood sugar levels are abnormally low, which is associated with taking too much insulin, digestive problems, or an inadequate diet (e.g., skipping a meal).
The assessment of a patient’s skin color can provide clues about their underlying health status. Abnormal skin colors may include:
Redness and flushing can be signs of infection or inflammation. Pallor can be a sign of anemia or blood loss. Cyanosis is a bluish tint to the skin that can be a sign of low oxygen levels in the blood.
Jaundice is a yellowing of the skin that can be a sign of liver disease or obstruction of the bile duct. Mottling is a marbled appearance of the skin that can be a sign of poor circulation.
The assessment of a patient’s pupils can provide clues about their level of consciousness and underlying health status. Abnormal pupil reactions may include:
- Pupil size
- Reactivity to light
Both pupils should be equal in size and shape, and they should react equally to light. If one pupil is larger than the other (anisocoria), it can be a sign of a serious condition, such as a brain tumor.
If the pupils do not react to light, it can be a sign of serious conditions, such as a stroke or cranial nerve damage.
Delirium is a state of confusion that can be caused by a number of medical conditions, such as infections, electrolyte imbalances, and drug toxicity.
It is often measured using the Confusion Assessment Method (CAM), which is a bedside test that assesses a patient’s level of consciousness, orientation, and ability to follow commands.
Patients with delirium often have abnormal vital signs, such as an increased heart rate and respiratory rate, and they may be at risk for falls and other injuries.
Vital Signs Practice Questions:
1. What are the most common Vital Signs?
Pulse Rate, Respiratory Rate, Blood Pressure, Body Temperature, and Oxygen Saturation.
2. What is the normal pulse rate?
3. Where can you find the pulse?
The radial, brachial, femoral, and carotid arteries.
4. What is the normal respiratory rate?
5. What is the normal Blood Pressure?
6. What is the normal body temperature?
Oral: 97.7–99.5 F (36.5–37.5 C); Axillary: 96.7–98.5 F (35.9–36.9 C); Rectal or ear: 98.7–100.5 F (37.1–38.1 C).
7. What is the normal Oxygen Saturation?
95–99% or greater than 93%.
8. What is the normal Heart Rate?
9. A low oxygen saturation is a good indicator of what?
10. What are complications with pulse oximeters?
Low perfusion, incorrectly fitted probe, the vascular bed is not pulsating dark fingernails, or the light is unable to pass through.
11. What is the accuracy range on a pulse oximeter?
+ or – 4%
12. What is the heart rate for someone who is bradycardic?
Less than 60 beats per minute.
13. What is the respiratory rate for someone who is tachypneic?
Greater than 20 breaths per minute.
14. What is the blood pressure for someone with hypotension?
Less than 90/60.
15. What is the breathing rate of someone who is apneustic?
Long gasping inspirations with insufficient expiration.
16. What are the primary causes of eupnea?
The normal physiology of being a human being.
17. Identify the following breathing pattern: Fast and deep breaths with periods of apnea and no set rhythm.
18. Which breathing pattern is normal in newborns and elderly, but abnormal for healthy adults?
19. What tool is required for listening when performing a manual blood pressure measurement?
20. Which part of a stethoscope allows a practitioner to hear sound during a manual blood pressure measurement?
The chest piece, which is made up of the diaphragm and bell
21. What is normally the heart rate for a newborn?
90–180 beats per minute.
22. What describes a patient’s heart rate that is greater than 100 beats/min?
23. What is DKA?
It stands for Diabetic Ketoacidosis. A shortage of insulin which causes the body to burn fatty acids and produce acidic ketone bodies.
24. The pulse rate and rhythm can be measured by what?
It can be measured by auscultation or palpation of any artery.
25. What arteries can be used for the pulse to be checked?
Radial Artery, Brachial Artery, Femoral Artery, Carotid Artery, and Pedal.
26. Which artery is most commonly used to check for a pulse?
27. How is pulse calculated?
The pulse is counted for 15 seconds and multiplied by 4 to get beats/minute.
28. How is respiratory rate measured?
By inspection of the movement of the chest for 1 minute.
29. What is the normal blood pressure for adults?
30. What is used to measure blood pressure?
31. What are the ways that the body temperature can be measured?
Orally, rectally, and axillary.
32. What is the normal body temperature?
37 degrees Celsius ( 97 degrees F).
33. What is fever?
A higher than normal body temperature (hyperthermia).
34. What is the normal pulse rate for an adult?
35. What does pulse oximetry estimate?
It noninvasively estimates the hemoglobin oxygen saturation of arterial blood.
36. What factors affect the accuracy of pulse oximetry reading?
Movement, bright light, extreme cold, extreme darkness, and high methemoglobin.
37. What would you call a respiratory rate less than 12?
38. What would you call a respiratory rate greater than 20?
39. What would you call a heart rate less than 60?
40. What would you call a heart rate greater than 100?
41. What is hypotension?
A blood pressure less than 90/60.
42. What is hypertension?
A blood pressure greater than 140/90.
43. What is the normal newborn pulse?
44. What is the normal 1-year-old pulse?
45. What is the normal preschool-age kid pulse?
46. What is the normal 10-year-old pulse?
47. What is the normal adult pulse?
48. What is the systolic blood pressure?
The top number which measures the pressure in the artery when the heart beats.
49. What is the diastolic blood pressure?
The bottom number that measures the pressure in the arteries when the heart muscle is resting.
50. How is the strength (amplitude) of a pulse measured on a scale?
4–bounding, 3–full, 2–normal, 1–diminished, and 0–absent.
51. What is bradycardia?
A slower than normal heart rate of less than 60 beats per minute.
52. What is tachycardia?
A faster than normal heart rate greater than 100 beats per minute.
53. What is hypotension?
Low blood pressure, which can cause dizziness or fainting (Less than 90/60).
54. What is hypertension?
High blood pressure, which can cause heart disease (Greater than 140/90).
55. What is eupnea?
A normal respiratory rate (12-20 breaths per minute), normal rhythm. Causes: normal physiology.
56. What is apnea?
The absence of breathing. Causes: respiratory or cardiac arrest and an increased intracranial pressure.
57. What are the types of pulse oximetry probes?
Finger probe, foot probe, toe probe, forehead probe, and ear probe.
58. Can cool or heated aerosols affect a body temperature reading?
Yes, yes they absolutely can.
59. Which vital signs provide information about gas exchange?
Oxygen saturation, heart rate, and respiratory rate
Vital signs are an important part of a routine medical assessment and can provide clues about a patient’s underlying health status. The most common vital signs include:
- Body temperature
- Heart rate
- Respiratory rate
- Blood pressure
- Oxygen saturation
Each of these vital signs can be measured using a variety of methods, and the normal ranges may vary depending on the age and health of the patient.
John Landry is a registered respiratory therapist from Memphis, TN, and has a bachelor's degree in kinesiology. He enjoys using evidence-based research to help others breathe easier and live a healthier life.
- Egan’s Fundamentals of Respiratory Care. 12th ed., Mosby, 2020.
- Wilkins’ Clinical Assessment in Respiratory Care. 8th ed., Mosby, 2017.
- Neonatal and Pediatric Respiratory Care. 5th ed., Saunders, 2018.
- Sapra, Amit, et al. “Vital Sign Assessment.” National Library of Medicine, Treasure Island (FL): StatPearls Publishing, Jan. 2022, www.ncbi.nlm.nih.gov/books/NBK553213.
- —. “Vital Sign Assessment.” National Library of Medicine, Treasure Island (FL): StatPearls Publishing, Jan. 2022, www.ncbi.nlm.nih.gov/books/NBK553213.
- Kebe, Mamady, et al. “Human Vital Signs Detection Methods and Potential Using Radars: A Review.” National Library of Medicine, Sensors (Basel), Mar. 2020, www.ncbi.nlm.nih.gov/pmc/articles/PMC7085680.