Vital Signs Assessment

What are Vital Signs?

Vital signs are measurements of the body to check your body’s basic functions. You might be thinking, why do we call them “vital signs,” right? This is because accessing vital signs is the first critical step used to assess patients.

If you’ve been to an emergency department, you have definitely seen a triage counter where nurses check their patient’s vital signs on their first encounter. This tells the physician how unstable the patient’s values are from the normal value.

As health care providers, it’s essential to know the conditions in which the measurements of vital signs change.

There are six main vital signs that healthcare professionals routinely monitor. These include;

  • Temperature
  • Pulse
  • Respirations
  • Blood pressure
  • Pain
  • Oxygen saturation

Mnemonic to remember it  is TPRBP-Ox

Vital signs are useful in detecting or monitoring medical problems. Vital signs can be measured in a medical setting, at home, at the site of a medical emergency, or elsewhere.

Why do we check vital signs?

In a case-control study conducted by Rothschild and colleagues, early warning criterion among patients on the medical floor, the presence of respiratory rate over 35/min was most strongly associated with a life-threatening adverse event. Thus, early warning score (EWS) tools, mostly using vital sign abnormalities, are critical in predicting cardiac arrest and death within 48 hours of measurement, even though the effect on in-hospital health outcomes and utilization of resources remains unknown.

It is advised that the earlier you detect the abnormalities, the earlier you can provide the correct treatment. This way, you can prevent diseases, complications, and even death.

Vital signs assessment helps in disease prevention and early intervention.

For example, I saw a patient with a 200/180 mm Hg blood pressure and mild headache during a routine examination. I immediately informed the doctor and administered an antihypertensive. In this scenario, if I had not checked the blood pressure, the patient would have ended up with severe complications like a stroke, angina, among other issues. This is why vital signs play an important role in providing timely interventions.

Now let’s discuss each vital sign one by one.


The human body temperature ranges from 6.5 to 37.5 degrees centigrade (97.7 to 99.5 degrees Fahrenheit). The hypothalamus of the brain regulates body temperature. Therefore, having an optimum temperature is necessary for optimum body and organ functioning. For example, our enzymes will not properly function at high temperatures.

The normal body temperature of a person varies depending on gender, recent activity, food and fluid consumption, time of day, and, in women, the stage of the menstrual cycle.

A person’s body temperature can be taken in different ways that include:


You can measure temperature by mouth using an oral thermometer such as the digital thermometers that use an electronic probe to measure body temperature.


You can check the body temperature through the rectum by using a rectal thermometer. Rectal body temperature is considered one of the most accurate measures of core body temperature. It tends to be 0.5 to 0.7 degrees Fahrenheit higher than when taken by mouth.


Temperatures can be taken under the arm using the same type of thermometer used in oral measurements. Temperatures taken by this route tend to be 0.3 to 0.4 degrees Fahrenheit lower than those temperatures taken by mouth.

By ear

A tympanic thermometer can quickly measure the temperature of the eardrum, which reflects the body’s core temperature (the temperature of the internal organs).

By skin

A temporal thermometer can quickly measure the skin’s temperature on the forehead, such as thermal guns.

In certain conditions, your body temperature gets abnormally high (hyperthermia) or low (hypothermia). While a traditional normal temperature reading is 98.6 degrees Fahrenheit, a fever is indicated when body temperature rises to 100.4 Fahrenheit. Conversely, hypothermia is defined as a drop in body temperature below 95 degrees Fahrenheit.

Did you know that in newborn babies, hypothermia is more serious than hyperthermia? Hypothermia is one of the leading causes of death in neonates; therefore, it is necessary to take proper measures to keep babies warm at normal temperatures. 


Pulse is also referred to as the heart rate. It is the measurement of heartbeats per minute. As the heart pushes blood through the arteries, the arteries expand and contract with the blood flow. By measuring the heart rate, you can assess the following things;

  • Heart rhythm
  • Strength of the pulse

The normal heart rate is 60 to 100 beats/minute. However, you should know about the conditions in which heart rate increases or decreases.  The pulse rate may fluctuate and increase with exercise, illness, injury, and emotions. Females ages 12 and older, in general, tend to have faster heart rates than males. Athletes, such as runners, who do a lot of cardiovascular conditioning, may have heart rates near 40 beats per minute and experience no problems.

How to check the pulse

As the blood passes through the arteries, you feel the pulse or beats by firmly pressing the arteries, which are located close to the surface of the skin at certain points of the body using your fingers.

You can assess the pulse on the sides of the neck (carotid pulse), inside the elbow (brachial pulse), or at the wrist (radial pulse).

For most people, it is easiest to check the pulse at the wrist. However, if you use the lower neck, be sure not to press too hard, and never press on the pulses on both sides of the lower neck at the same time to prevent blocking blood flow to the brain. When checking the pulse:

  1. Press firmly but gently on the arteries using your first or second finger until you feel the beat.
  2. Begin counting the pulse by keeping an eye on the clock.
  3. Count the pulse for 60 seconds (or for 15 seconds, and then multiply by four to calculate beats per minute).
  4. Focus on counting the beats.
  5. If unsure about the results, ask another person to count for you.

Have the patient calm and in a relaxed position before measuring the pulse.

Respiratory rate or respirations

The respiratory rate is the number of breaths the person takes in a minute. The rate is usually measured when a person is at rest and involves counting the number of breaths for one minute by counting how many times the chest rises.

Respiration rates may increase with fever, illness, and other medical conditions. Therefore, it is important to note whether a person has any difficulty breathing when checking respiration.

Normal respiration rates for an adult at rest range from 12 to 20 breaths per minute.

Blood pressure

Blood pressure is the pressure or force exerted against the walls of the arteries during contraction (systole) or relaxation (diastole) of the heart.

Each time the heartbeats, it pumps blood into the arteries resulting in the highest blood pressure as the heart contracts. When the heart relaxes, the blood pressure falls.

You might have noticed that blood pressure is recorded in a two-number form. The higher number, or systolic pressure, refers to the pressure inside the artery when the heart contracts and pumps blood through the body. The lower number, or diastolic pressure, refers to the pressure inside the artery when the heart is at rest and fills with blood. Both the systolic and diastolic pressures are recorded as “mm Hg” (millimeters of mercury).

Normal blood pressure is 120/80 mm Hg, but it depends on age, gender, and underlying co-morbidities. Always check for the person’s baseline before marking them as normotensive, hypotensive, or hypertensive.


Hypertension means high blood pressure. It directly increases the risk of heart attack, heart failure, and stroke. With high blood pressure, the arteries may have an increased resistance against blood flow, causing the heart to pump harder to circulate the blood.

Categories of blood pressure

  • Normal blood pressure is systolic of less than 120 and diastolic of less than 80 (120/80)
  • Elevated blood pressure is systolic of 120 to 129 and diastolic less than 80.
  • Stage 1 high blood pressure is systolic is 130 to 139 or diastolic is between 80 to 89.
  • Stage 2 high blood pressure is when systolic is 140 or higher or the diastolic is 90 or higher.

Remember, a single reading of blood pressure is insufficient to assess someone for high and low blood pressure. In fact, we want to see multiple blood pressure measurements over several days or weeks before making a diagnosis of high blood pressure and starting treatment. In addition, always encourage your patients to record their readings to see the trends to prescribe accurate treatment.

However, in an acute setting, it is important to alert the physician or provider when you notice that the blood pressure has fallen outside of the normal range.

How to check blood pressure

You can check blood pressure digitally using a digital meter or manually using an aneroid monitor or sphygmomanometer.

Manual blood pressure measurement (palpatory method)

To check blood pressure without the aid of an automated machine, You will need several medical items. Which Include:

  • a stethoscope
  • A blood pressure cuff with a squeezable balloon and an aneroid monitor that has a numbered dial to read measurements.

Make your patient sit comfortably on a chair with the arm at rest on a table. Secure the cuff on the bicep and squeeze the balloon to increase the pressure.

Watch the aneroid monitor, increase the pressure to about 30 mm Hg over normal blood pressure or 180 mm Hg if this is unknown. When the cuff is inflated, place the stethoscope just inside the elbow crease under the cuff.

Slowly deflate the balloon and listen through the stethoscope. When the first beats hit, note the number on the aneroid monitor. This is systolic pressure.

Continue listening until the steady heartbeat sound stops and record the number from the aneroid monitor again. This is the diastolic pressure. These two numbers are the blood pressure reading.

Nursing pearls for blood pressure measurement

When checking the blood pressure, it is important to remember:

  • Manual cuffs come in different sizes, depending on the size of the arm. Using the right size ensures the most accurate reading.
  • The cuff should always sit directly on the bare skin.
  • Ask the patient to take a few deep breaths and relax for up to 5 minutes before measuring blood pressure.
  • Avoid talking during the test.
  • Place the client’s feet flat on the floor and sit up straight while measuring the blood pressure.
  • Avoid checking blood pressure in a cold room.
  • Support the arm of the patient as close to heart level as possible.
  • Measure the blood pressure at a few different times during the day.
  • Encourage the patient to avoid smoking, drinking, and exercise for 30 minutes before taking blood pressure.
  • Ask the patient to empty the bladder before taking a blood pressure test. A full bladder may give an incorrect blood pressure reading.

Digital blood pressure measurement

Taking a digital blood pressure is easy and quick. You can simply secure the cuff on the client’s arm and press the “start” button. It will automatically take the blood pressure and give a reading on the screen.

However, sometimes the readings are not quite accurate; therefore, you may need to confirm it with manual BP apparatus.


Pain is  also a vital sign. Often, nurses and health professionals ignore this due to time pressure, but it is crucial as an early warning sign for detecting disease. Since pain is subjective, self-report is considered the Gold Standard and most accurate measure of pain.

Pain occurs due to many physiological changes in the body, such as inflammation, internal organ damage/injury, bleeding, etc.

How to assess pain?

The PQRST method of assessing pain is a valuable tool to accurately describe, assess, and document a patient’s pain. The method also aids in the selection of appropriate pain medication and evaluating the response to treatment.

Nurses can help patients report their pain more accurately by using these concrete PQRST assessment questions:


What were you doing when the pain started? What caused it? What makes it better or worse? What seems to trigger it? Stress? Position? Certain activities?

What relieves it? Medications, massage, heat/cold, changing position, being active, resting?

What aggravates it? Movement, bending, lying down, walking, standing?

Q = Quality/Quantity

What does it feel like? Use words to describe the pain, such as sharp, dull, stabbing, burning, crushing, throbbing, nauseating, shooting, twisting, or stretching.

R = Region/Radiation

Where is the pain located? Does the pain radiate? Where? Does it feel like it travels/moves around? Did it start elsewhere and is now localized to one spot?

S = Severity Scale

How severe is the pain on a scale of 0 to 10, with zero being no pain and 10 being the worst pain ever? Does it interfere with activities? How bad is it at its worst? Does it force you to sit down, lie down, slow down? How long does an episode last?

T = Timing

When/at what time did the pain start? How long did it last? How often does it occur: hourly? Daily? Weekly? Monthly? Is it sudden or gradual? What were you doing when you first experienced it? When do you usually experience it: daytime? Night? Early morning? Are you ever awakened by it? Does it lead to anything else? Is it accompanied by other signs and symptoms? Does it ever occur before, during, or after meals? Does it occur seasonally?

Nursing pearls for Pain documentation

In addition to facilitating accurate pain assessment, careful and complete documentation demonstrates that you are taking all the necessary steps to ensure your patients receive the highest quality pain management. It is important to document the following:

  • Patient’s perception of the pain scale. Describe the patient’s ability to assess pain level using the 0-10 pain scale.
  • Patient satisfaction with pain level with current treatment modality. Ask the patient what their pain level was before taking pain medication and after taking pain medication. If the patient’s pain level is not acceptable, what interventions were taken?
  • Timely re-assessment following an intervention and response to treatment. Quote the patient’s response.
    Communication with the physician. Always report any change in condition.
  • Patient education provided and the patient’s response to learning. Don’t write “patient understands” without a supportive evaluation such as the patient can verbalize, demonstrate, describe, etc.

Oxygen Saturation

Oxygen saturation or O2 Sats is our sixth vital sign which indicates the amount of oxygen traveling through the body with the red blood cells. Normal oxygen saturation is usually between 95% and 100% for most healthy adults.

How to measure O2 Sat?

As part of vital signs, we measure it non-invasively with the help of a pulse oximeter. However, in critically ill clients, a more invasive and continuous monitoring system is used to measure arterial blood gases through an arterial line.

Because the device primarily measures light absorption of pulsatile flow (the ‘p’ in Sp02 refers to pulse or pulsatile flow), pulse oximeter readings represent arterial oxygen saturation levels rather than venous oxygen saturation levels. An oxygen saturation level will not be correct if the pulsatile flow is restricted or impeded. Blood pressure and pulse oximetry should not be taken on the same limb because the compression of a blood pressure cuff will obliterate the pulsatile flow.

A clip is applied at the finger of the client which consists of the sensor to measure oxygen saturation, and you can see the reading on the monitor. Always keep in mind that when the patient is moving, a lot of vibrations take place, so the reading appears on the screen is incorrect; therefore, keep the patient calm and relaxed, then apply the saturation probe (clip) and watch for a regular graph in order to get the most accurate reading.

Nursing Pearls

  • Hypoxemia is a condition in which the client’s oxygen saturation is below the normal range, thus as a nurse, you should ask him or her to perform deep breathing exercises.
  • Assess the client for airway patency and air entry.
  • In case of severe shortness of breath and persistent hypoxemia, you need to administer supplemental oxygen to prevent cellular death.
  • To improve gaseous exchange, keep the patient in semi-fowlers or fowler’s position because it promotes lung expansion.
  • Keep in mind that whenever supplemental oxygen is being administered, consider using humidified oxygen (through humidifier) to avoid mucosal dryness and irritation.
  • The patients with COPD should not be hyper oxygenated, rather, their appropriate oxygen saturation should be kept between 88-92%.

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