Lesson · 26 min

Measuring and Reporting Vital Signs

Take accurate vital signs, recognize changes from a patient's baseline, and report what matters immediately.

By the end of this lesson you can

Measure each vital sign using correct technique
State expected adult ranges and recognize deviations
Compare a reading against the patient's own baseline
Identify readings requiring immediate escalation

📘 Reading Lesson

Lesson Notes

Read through the key concepts before you try the challenge.

Taking a blood pressure you would stake a decision on

Worked example

Getting an accurate reading under time pressure

Measure a blood pressure on a busy round, accurately enough that a clinician can act on it without retaking it.

1
Let the patient sit quietly for five minutes, feet flat and back supported.
This is the step time pressure removes first, and it is the largest single source of falsely high readings. Crossed legs raise systolic pressure and an unsupported back raises diastolic. Five minutes costs less than a patient started on medication they do not need.
2
Size the cuff to the arm rather than using the one already attached.
The bladder should encircle about 80% of the arm. A cuff that is too small reads high by 10 to 20 mmHg — enough on its own to move a patient into a different category. This is the most common equipment error in the building.
3
Bare arm, supported at heart level.
A sleeve under the cuff distorts the reading and a pushed-up sleeve becomes a tourniquet. An arm below heart level reads high. And support it yourself — a patient holding their own arm up is using muscle, which also raises the number.
4
Palpate first, then inflate 30 mmHg above where the pulse disappeared.
This avoids missing an auscultatory gap — a silent interval where the sounds vanish and return. Miss it and you record a systolic far below the real one, which is the error that reads as reassuring.
5
Deflate slowly, 2 to 3 mmHg per second.
Faster deflation misses the true first and last sounds, underestimating systolic and overestimating diastolic. It is the error that feels like efficiency.
6
Record the arm, the position, and the cuff size alongside the number.
It makes the reading comparable at the next check. A pressure recorded with no context cannot be meaningfully compared to one taken differently, and the trend is usually what matters.

Result: A reading that reflects the patient's pressure rather than your technique.

Rest, cuff size, bare arm at heart level, palpate first, deflate slowly. Every error pushes the number in a predictable direction, and they add up.

The trend matters as much as the number

On the job

You take routine vitals on a medical unit at Lakeside Regional.

A patient's heart rate is 98. That is inside the normal range, so it is easy to record and move on. Their rate has been 62 every shift for three days. A jump of 36 beats in one patient is a change worth reporting, and the normal range conceals it entirely.

Your task: Read every measurement against that patient's own baseline, not only against the textbook range.

Vital sign	Range	Note
Temperature	97.0-99.0°F oral	Route affects the reading; be consistent
Pulse	60-100 bpm	Record rate, rhythm, and strength
Respirations	12-20 per minute	Count discreetly — awareness changes the rate
Blood pressure	Below 120/80 normal	Technique errors mostly push it up
Oxygen saturation	95-100%	Cold hands, nail polish, poor perfusion cause false lows
Pain	0-10, self-reported	The patient's number is the number

Expected adult ranges

A value inside the normal range can still be a significant change. A patient whose pulse has been 62 for three days and is now 98 has changed substantially, even though 98 is 'normal.' The same is true for a blood pressure that drops 30 points while remaining within range. Report the change, not just the out-of-range value — this is one of the most valuable things a PCT does.

Error	Effect
Cuff too small	Falsely high, often by 10-20 mmHg
Cuff too large	Falsely low
Arm below heart level	Falsely high
Patient talking during measurement	Falsely high
Deflating faster than 2-3 mmHg/second	Systolic low, diastolic high
No rest before measuring	Falsely high
Nail polish or cold fingers on a pulse oximeter	Falsely low saturation

Technique errors and their direction

Report immediately rather than waiting for handoff: oxygen saturation below 90%; systolic above 180 or below 90; heart rate above 120 or below 50; respirations below 12 or above 24; temperature above 100.4°F; any significant change from baseline; and any abnormal reading accompanied by symptoms such as chest pain, breathlessness, or confusion. You are not deciding what it means — you are making sure the nurse knows in time.

Check your understanding

A patient's pulse has been 60-65 for three days. Today it is 98. What should you do?

Challenge

Apply what you've learned in this lesson.

Vital signs are a hands-on skill; this is the knowledge that must precede supervised practice.

Write the expected adult ranges for all six vital signs from memory, then check.
For each error in the table, state the direction and rough magnitude of its effect.
For a patient whose blood pressure has been 138/84 and is now 96/58, write the report you would give the nurse in under twenty words.
List eight readings that would prompt you to notify the nurse immediately rather than at handoff.

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EKG and Point-of-Care Testing →