What Are Vital Signs

The word vital came from the Latin word "Vitalis", meaning "of or belonging to life". It comes as no surprise that vital signs are used ubiquitously in clinical and healthcare settings. It is the first set of parameters that is used in clinical examinations. Doctors, paramedics, nurses, and other healthcare professionals use Vital signs in outpatient and inpatient settings, clinics, hospitals, and ambulances for the patient's initial assessment. Vital signs indicate a person's basic functional and physiological characteristics.

Blood pressure, pulse pressure, temperature and respiratory rate are traditionally used in clinical settings. However, it is also customary in clinical settings nowadays to look at oxygen saturation (SpO₂), blood glucose level and pain level for a patient's overall assessment.  

Blood pressure

How do I check my blood pressure?

Blood pressure is a force or pressure used to pump the blood in your body. Blood pressure readings are vital as could give you a picture of whether your body is haemodynamically stable or not. Blood pressure is also crucial as it could indicate and provide a snapshot of certain diseases such as coronary heart disease, end-stage renal failure,¹ and even respiratory issues. Hence, it is essential to get an accurate reading of blood pressure.

An instrument called a sphygmomanometer is used to measure blood pressure. When measuring blood pressure in clinical or non-clinical settings, it is best to do it in a relaxed, quiet environment and a seated position. It is also advisable for the person measuring their blood pressure for their arm to be outstretched and supported while measuring the blood pressure. 

A blood pressure cuff also plays a vital role in accurate measurement. Always use an adult blood pressure cuff for adult patients and a paediatric blood pressure cuff for children, as this could give a vast difference in measurement. The unit used to represent blood pressure is called millimetre mercury, mmHg. Once blood pressure is measured, it will show two figures - systolic and diastolic blood pressure. Blood pressure measurement is also repeated consecutively within one minute apart for an accurate reading.

When blood is pushed out of your heart, it is called systolic pressure. On the other hand, when the heart rests in between the pump, it is called diastolic pressure, indicating that the heart is currently resting from pumping. A blood pressure showing 120/80 mmHg means that you have a systolic pressure of 120mmHg and a diastolic pressure of 80mmHg.

Hypotension and hypertension

Low blood pressure is called 'hypotension' but is less common than high blood pressure or 'hypertension'. According to the National Institute of Health and Care Excellence (NICE) guidelines - to confirm the diagnosis of hypertension, there must be a measurement of blood pressure of 140/90mmHg or higher in a clinic setting or blood pressure reading of 135/85 mmHg or more in Home Blood Pressure Monitoring (HBPM) or Ambulatory Blood Pressure Monitoring (ABPM)²

Hypertension is usually related to smoking, overweight or obese, sedentary lifestyle or coronary heart diseases. Hypotension (blood pressure below 90/60mmHg) could indicate a low perfusion, such as dehydration and shock. An ideal blood pressure should be within 90/60mmHg and 120/80mmHg.

Pulse rate

Tachycardia and bradycardia

The number of times our heart beats in a minute is called 'pulse rate'. A normal heartbeat or pulse rate is 60 to 100 beats per minute. A slow heart rate, less than 60 beats per minute, is called 'bradycardia' and 'tachycardia' describes when the heart beats more than 100 beats per minute. Although heart and pulse rates seem similar, they are not the same. Heart rate is the measurement of how fast a heart is beating, and pulse rate is how you can feel this heart beating (it is the pressure felt in arteries as it briefly goes up as the heart pumps blood out of it for whole body circulations and the pressure goes down when the heart relaxes in between pumps).

We could routinely check our pulse rate by ourselves without any instruments. Pulse can be felt by gently pressing the first and second fingertips against specific pulse points on the body. There are a few locations to feel for a pulse. The most common and easily palpable is the wrist's radial artery or the neck's carotid artery. Either risk could be palpable for radial pulse. While the palm facing upwards, using the tips of the first and second fingers of the other hand, gently palpate the pulse in the radial artery (palpate between the wrist bone and the tendon on the thumb side of the wrist). It is important not to apply too much pressure to prevent obstructing blood flow. During palpating the pulse, counting the heart rate within 60 seconds is recommended.

Why do I need to check my pulse rate?

The importance of checking for pulse rate lies in the significance of stroke prevention.³ An irregular pulse could be caused by heart rhythm abnormalities such as Atrial Fibrillations (AF). Atrial fibrillations happen when the electrical signal in the heart originates from different places in the atria (two upper chambers of the heart) instead of from one primary origin (sinoatrial nodes and atrioventricular nodes). This phenomenon could cause disturbed electrical activity in the heart, making the heart contract or pump irregularly, resulting in blood accumulations in the heart called blood clots.⁴

Blood clots from atrial fibrillations caused by irregular heart rhythm risk travelling to other parts of the body, such as the brain, which can cause a  stroke. It could also lead to heart failure. Hence, it is a good idea to check your pulse occasionally or get a physical examination from an expert like a nurse  or doctor.

Respiratory rate

The number of breaths you take each minute is called the respiratory or breathing rate. The standard respiratory rate ranges from 12-20 breaths per minute in adults, 30-60 breaths per minute in infants within one year, and 24-40 breaths per minute in children aged one to three. For children aged four to five years old, the average breathing rate is between 22 and 34 breaths per minute; for school-aged children between the ages of six and twelve, the average breathing rate is 18-30.

What can cause tachypnea and bradypnea?

Several factors influence respiratory rates. A higher respiratory rate of more than 20 breaths per minute is described as Tachypnea. It could be due to physiological conditions such as exercise, emotional changes or pregnancy. On the other hand, pathological conditions such as asthma, pneumonia, diabetic ketoacidosis, and heart failure could also cause someone to be tachypneic. When the respiratory rate is less than 12 breaths per minute, it is called Bradypnea, and it is due mainly to pathological conditions such as alcohol and drug intoxication or overdose.

Body temperature

Ever notice your body feeling somewhat hot or feverish when sick or becomes cold after exercising? That is because of the temperature regulations of your body. The average body temperature of a person is between 36.4 degrees Celcius (^OC) and 37.4 degrees Celcius (^OC). Temperature is measured using a thermometer placed over a person's mouth or rectum. A thermometer could also be placed at the axillary or armpit to monitor temperature. With modern technology, many advanced thermometers can detect the temperature by scanning or measuring the skin over the forehead or ear.

Fever, prolonged fever and fever of unknown origin

A body temperature higher than 38^OC is a fever state; a temperature below 35^OC is called hypothermia. However, body temperature is entirely subjective to every individual. A menstruating woman could have a higher body temperature than usual. The same goes for an athlete who could have a colder body temperature right after exercising. Factors or conditions such as ongoing infections, dehydration, sunburn, and hormonal changes such as thyroid issues (hyper or hypothyroidism) could also affect body temperature.⁵

Suppose a fever persists for over two weeks and other symptoms such as anorexia, weight loss, and malaise. In that case, it is granted for further and thorough investigations to take place in a hospital setting. Diseases or conditions such as malaria, HIV, and tuberculosis should be ruled out.⁵

Upon complete examinations by physical examination, chest x-rays, routine blood tests, and cultures to try and elude the diagnosis of prolonged fever of more than two to three weeks come to no avail reason or diagnosis, and it is treated as fever of unknown origin or pyrexia of unknown origin. Diseases like bacterial endocarditis, biliary tract diseases such as liver or abdominal abscesses, and neoplasms such as Hodgkin or Non-Hodgkin Lymphomas could be why this fever is of unknown origin. 

Sometimes, it takes some time for the laboratory to develop one diagnosis, depending on the healthcare practitioner's expertise and experience. However, the patient will usually be covered with broad-spectrum antibiotics, and the patient's progress will be closely monitored while further investigation occurs.

Summary

As a language in healthcare, vital signs are essential markers that allow healthcare professionals to understand more of the human body. Traditionally, the quartet of blood pressure, pulse rate, respiratory rate, and body temperature has been the cornerstone of vital sign assessments. These four parameters paint a dynamic picture of one health status as they offer insights into an individual's fundamental functional and physiological aspects.

Maintaining normal blood pressure is essential to avoid worsening conditions such as coronary heart disease, heart failure and end-stage renal failure. Early detection of irregular heart rate could be the cornerstone of stroke prevention as atrial fibrillation is diagnosed early. Respiratory rate and temperature became the clinical guidelines in hospital settings for patient improvement upon treatment administered. It is clear that vital signs are essential for a patient’s clinical assessment.