Vital Signs Basics


Published: 10 September 2019

This article provides a brief overview of vital signs and is to be used in conjunction with your organisation's policies and procedures.

Note: this article does not encompass reasons why or when to conduct a vital sign assessment - rather, it serves to be used as a summary of each vital sign. All ranges listed are for an adult and this overview does not discuss paediatrics.

Level of Consciousness

The first vital sign that a healthcare worker may note is a client’s level of consciousness.

AVPU Assessment

A rapid assessment tool that is utilised in the healthcare field to measure conscious state is the AVPU scale.

  • A stands for Alert

    The client is aware of the environment and is opening their eyes spontaneously.

  • V stands for Verbal

    The client’s eyes do not open spontaneously, rather their eyes open in response to a verbal stimulus directed towards them.

  • P stands for Pain

    The client's eyes do not open spontaneously or to verbal stimuli, the patient will only respond to painful stimuli directed towards them. A pain stimulus includes touch and if still no response, the health professional can attempt other painful stimuli such as the trapezius squeeze.

  • U stands for Unresponsive

    The client is not responding spontaneously, or to verbal or painful stimuli (Romanelli & Farrell 2019).

Glasgow Coma Scale

To further assess the level of consciousness in a client, the Glasgow Coma Scale (GCS) can be utilised for a more in-depth approach. Details on the GCS assessment can be found at

Important Considerations

Some factors, which may influence a person’s level of consciousness include but are not limited to sleeping, alcohol and medications.

Respiratory Rate

What is a respiratory rate?

Respiratory rate is the number of breaths a person takes per minute.

Respiratory rate assessment:

Respiratory rate changes are the first sign of medical deterioration but are frequently measured inaccurately (Rolfe 2019). It is through watching the rise and fall of the chest, or placing hands on the person’s chest or back and counting breaths for a full minute that this important vital sign can be measured accurately.

Normal respiratory rate:

The normal limit for an adult respiratory rate is considered to be between 12 and 20 breaths per minute (Lough 2015).

Note that children have different normal ranges to adults and these ranges change depending on their age.

Important considerations

Further, as well as assessing the respiratory rate, it is also crucial to note other aspects of a respiratory assessment such as work of breath, advantageous sounds or lack of sounds (Bellani & Pesenti 2014).

A patient’s respiratory rate is influenced by factors including whether the patient is a rest or has been moving.

Oxygen Saturation

Patient in bed | Image

This vital sign ensures that hypoxia is noticed in a patient as well as to evaluate the effectiveness of oxygen therapy.

Oxygen Saturation Asessment

This observation is generally measured through pulse oximetry.

Normal oxygen saturation range

The normal range of oxygen saturation for a person is considered to be a peripheral capillary oxygen saturation (SpO2) above 95%, however, this may be individualised for patients who retain carbon dioxide, such as people with a chronic obstructive pulmonary disease with potential SpO2 aims being between 88-92% (O’Driscoll et al. 2017).

Important considerations

The results can be influenced by nail polish on the used fingernail that the reading is being gained from, oedema, cold extremities with poor blood flow as well as oxygen administration (Seifi et al. 2018).

Blood Pressure

What is blood pressure?

Blood pressure is the force of blood as it flows through the artery walls during contraction and relaxation of the heart and is measured in millimetres of mercury (mmHg).

Blood pressure assessment:

This vital sign takes into account systolic and diastolic measurements. A normal systolic range is between 100 to 140mmHg and a normal diastolic is between 60 and 89mmHg (Lough 2015).

A high blood pressure, hypertension or low blood pressure, hypotension are signs of clinical deterioration and must be actioned on appropriately by medical staff. Manual blood pressures should be taken to ensure the accuracy of the results.

Blood pressure can also be measured from lying to standing to determine if there is a postural drop. A postural drop increases a patient’s risk of dizziness and falls (Clark et al. 2018).

Normal blood pressure range:

The normal range is dependant on the person's age and fitness status.

Further, it is important that health professionals note that drastic changes in blood pressure - although may be considered in the normal range - can be a sign of clinical deterioration. It is vital that healthcare staff monitor the trends of data to understand what is normal for each patient as this is highly individualised (Lough 2015).

Note that children have different normal ranges to adults and these ranges change depending on their age.

Important considerations:

Activities, which may influence results include exercise and pain, and this must be considered in the documentation.

Heart Rate

What is heart rate?

The heart rate is how many times the heart beats per minute.

Normal heart rate range:

The normal range is between 60 to 100 beats per minute (Lough 2015). This result may be influenced by fitness level, age, illness and emotion. During measurement of the heart rate, one can also note heart rhythm and strength of the pulse.

Note that children have different normal ranges to adults and these ranges change depending on their age.


Normal temperature range:

Temperature is how hot or cold a person is and a normal range is considered to be between 36.5 to 37.5 degrees Celsius (Lough 2015).

Temperature assessment:

This vital sign can be measured in a variety of ways including, orally, rectally, axillary, tympanic or through scanning the skin on the forehead.


Often considered the 5th vital sign, it is important to incorporate a pain assessment into a person’s regular observations.

For more details:


There is a dipstick test, which is available to provide results regarding pH, protein, glucose, ketone, bilirubin, blood, urobilinogen, nitrite, leukocyte esterase. Urine should aim to be tested within 4 hours of collection.

Dipstick test:

A dipstick — a thin, plastic stick with strips of chemicals on it — is placed in the urine to detect abnormalities. The chemical strips change color if certain substances are present or if their levels are above normal.

A dipstick test checks for acidity, concentration via specific gravity, glucose, leukocytes, nitrite, protein, blood, ketones, bilirubin and urobilinogen. The dipstick test is a helpful diagnostic tool in identifying conditions such as urinary tract infections (Royal College of Pathologists of Australasia 2019).


Weight is a measurement that is generally performed on admission and weekly thereafter, unless there are specific circumstances (e.g. fluid overload risk, eating disorder risk) where weighs may be completed more frequently.

A person’s weight number is vital in medication dosage as well as assessing nutritional status. If measuring weight, it is imperative that the weighing is completed on the same scale for consistency and to reduce the inaccuracy of results. Further, in measuring fluid status, it is important that a person is weighed at the same time of day and in roughly the same amount of clothing to appropriately assess fluid balance (Evans & Best 2014).

Blood Glucose Levels

Blood glucose levels (BGL) are another important observation for healthcare workers to partake in as they can have various adverse outcomes if not checked. BGL is measured in millimoles per litre (mmol/L) and a normal range is considered to be 4.0 to 7.8 mmol/L, though people with diabetes may have discussed individual target ranges with their doctor.

Measurement of blood glucose level must be completed by a meter that is calibrated, and times of day decided on by the medical team (Diabetes Australia 2015).

Hyperglycaemia and hypoglycaemia both have negative impacts on patients, more detail can be found at and



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