Vital signs are measurements of the body’s most basic functions—body temperature, rate of respiration (breathing), pulse rate, blood pressure, and oxygen saturation (amount of oxygen circulating in the blood). Medical professionals use these five measurements to assess one’s general health, detect and monitor medical conditions, and monitor treatment effectiveness.
Compared to high-tech medical tests, measuring a person’s vital signs is relatively simple, requiring some basic medical equipment—a thermometer, stethoscope, blood pressure cuff—and a stopwatch or other timing device. The information obtained can, in some cases, be a matter of life and death, or at least sickness and health.
Although factors such as age, sex, weight, and activity level can play a role in what an individual’s vital signs might indicate, there is agreement across the medical community about what’s normal for adults in general.
Respiration rate refers to the number of breaths taken per minute while at rest. It’s one of the easiest vital signs to measure, as you only need a clock or timer.
To determine your respiration rate, set a timer for one minute and count the number of times your chest rises and falls until the timer goes off. It may be helpful to enlist a loved one or care provider to help you measure your respiration, as observing your own breath may cause you to breathe more slowly than you naturally would, leading to an inaccurate result.
The normal number of breaths per minute for an adult at rest is 12 to 18.
A respiration rate that’s slower than normal ( bradypnea ) or that’s fast and shallow ( tachypnea ) is an indication of potential health problems.
Potential Causes of Abnormal Respiratory Rate | |
---|---|
Bradypnea | Tachypnea |
Narcotic use (for medical or recreational purposes) | Fever, infection |
Alcohol use | Dehydration |
Metabolic problems (hypothyroidism) | Lung disease (COPD, lung cancer, asthma) |
Sleep apnea (only while asleep) | Panic/anger/stress |
Certain brain conditions, such as stroke or head injury | Acidosis (increase in blood acidity) |
Drug overdose | Drug overdose |
A person’s pulse is created by the surge of blood through the arteries when the heart beats. Pulse rate is a measurement of how many times per minute this surge can be detected.
The normal resting pulse for a healthy adult ranges from 60 beats per minute to 100 beats per minute, although there can be variations—notably among athletes. Those who do a lot of cardiovascular training may have a resting pulse as low as 40 beats per minute because their hearts are strong enough to pump a greater-than-normal amount of blood per beat.
A pulse can be felt most easily on the side of the neck, the inside of the wrist (the radial pulse), and the inside of the elbow—areas where arteries are located close to the surface of the skin.
To take your pulse at the wrist, you will need a watch with a second hand:
The pulse rate also can be measured at the neck, but it’s important to not press on the pulses on both sides of the lower neck; doing so could risk blocking blood flow to the brain.
Besides counting when checking someone’s pulse, it’s important to pay attention to how strong or weak the pulse is and how steady, or regular, it is. The speed, strength, and rhythm of the pulse can reveal a lot about the health of the heart, as well as point to signs of diseases or conditions that may affect how the heart functions.
A slow pulse (bradycardia) can indicate:
A rapid pulse (tachycardia) can indicate:
Blood pressure refers to the force of blood pushing against the walls of the arteries every time the heart beats. Blood pressure readings contain two numbers (e.g., 120/80 millimeters of mercury, or mmHg):
An instrument called a sphygmomanometer is used to measure blood pressure. It consists of a cuff that is placed around the upper arm and a small pump that fills the cuff with air, squeezing the arm until the circulation is cut off.
At this point, a small valve opens to allow air to slowly leak out of the cuff. As it deflates, the medical professional will hold a stethoscope against the inside of the elbow to listen for the sound of blood pulsing through the arteries.
The first sound will be the systolic pressure; the second is the diastolic pressure. A meter that’s part of the sphygmomanometer indicates the specific numbers that correspond to each.
There are blood pressure monitors available for home use as well. These monitors use an arm cuff connected to a blood pressure measurement device. They are easy to use and provide accurate readings. If you want to purchase a home blood pressure monitoring device, choose one that is certified by the American Medical Association’s Validate BP list. These devices have been validated for clinical accuracy.
Whether checking your blood pressure at a healthcare facility or measuring it at home, take these steps to get a more accurate reading:
Blood pressure readings that are either higher than normal or lower than normal may indicate certain health problems.
The American Heart Association recognizes the following categories of blood pressure readings that are higher than normal (hypertension):
Category | Blood Pressure Reading |
---|---|
Elevated BP | Readings that consistently range from 120 mmHg to 129 mmHg systolic and less than 80 mmHg diastolic |
Hypertension stage 1 | Readings that consistently range from 130 mmHg to 139 mmHg systolic or 80 mmHg to 89 mmHg diastolic |
Hypertension stage 2 | Readings that consistently are 140/90 mmHg or higher |
Hypertensive crisis | A reading that suddenly exceeds 180 mmHg systolic and/or 120 mmHg diastolic and remains high when measured a second time after five minutes: This stage of high blood pressure requires immediate medical attention. |
There are hereditary and physical risk factors for high blood pressure, including:
When blood pressure is lower than normal (hypotension), it means the heart can no longer deliver an adequate supply of blood to the body. This can occur because of an underlying health condition such as anemia, a heart problem, or an infection. Dehydration or certain medications also can cause a drop in blood pressure.
Chronically low (or even borderline low) blood pressure can have an adverse effect on the kidneys. In rare instances, a dramatic drop can lead to syncope (fainting), shock, coma, and even death.
Oxygen saturation is the amount of oxygen in your blood. Oxygen travels through the bloodstream to the body’s organs and tissues and is critical for them to work properly,
For most healthy adults, a normal oxygen saturation level is between 95% and 100%.
You can check your oxygen saturation rate at home with a device called a pulse oximeter. This device uses a light source that passes through the finger and a sensor is able to calculate the oxygen in the red blood cells.
To use a pulse oximeter, you insert your finger into the device. You will feel a slight pressure, but it doesn't cause pain. Most devices beep or stop flashing when the measurement is complete.
There are many conditions that can cause low levels of oxygen in the blood (hypoxemia), including:
Warning signs of a low oxygen level include trouble breathing, confusion, difficulty waking up, and bluish lips or face. If your oxygen saturation is less than 95%, you should talk to your healthcare provider. An oxygen saturation of 90% or less is considered a medical emergency requiring medical help right away.
14 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
By Deborah Leader, RN
Deborah Leader RN, PHN, is a registered nurse and medical writer who focuses on COPD.
Verywell Health's content is for informational and educational purposes only. Our website is not intended to be a substitute for professional medical advice, diagnosis, or treatment.
Ⓒ 2024 Dotdash Media, Inc. — All rights reserved Verywell Health is part of the Dotdash Meredith publishing family.We and our 100 partners store and/or access information on a device, such as unique IDs in cookies to process personal data. You may accept or manage your choices by clicking below, including your right to object where legitimate interest is used, or at any time in the privacy policy page. These choices will be signaled to our partners and will not affect browsing data.
Store and/or access information on a device. Use limited data to select advertising. Create profiles for personalised advertising. Use profiles to select personalised advertising. Create profiles to personalise content. Use profiles to select personalised content. Measure advertising performance. Measure content performance. Understand audiences through statistics or combinations of data from different sources. Develop and improve services. Use limited data to select content. List of Partners (vendors)