Certified Nursing Assistant (CNA) Exam: Vital Signs, Measurements, and Reporting Concepts
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Overview
This chapter covers measuring vital signs, height and weight, and intake and output, and reporting what you observe. Questions often ask about normal adult ranges and when to report.
For adults at rest, a normal pulse is about 60 to 100 beats per minute and normal breathing is about 12 to 20 breaths per minute. The radial pulse is on the thumb side of the inner wrist. Count an irregular pulse for a full minute. Count breathing without the resident noticing, because people change how they breathe when they know it is being counted.
The average normal oral temperature is about 98.6°F (37°C). Rectal readings are usually highest and axillary (armpit) readings lowest. Normal adult blood pressure is below 120 over below 80, and a cuff that is too small can give a falsely high reading.
For intake, count anything that is liquid at room temperature, such as gelatin and soup, and use 1 ounce = 30 mL. Weigh the resident at the same time, on the same scale, in similar clothing. Pain is what the resident says it is, so report the resident's own rating. Report any sudden change, such as new confusion, to the nurse right away.
Key concepts
Pulse
The heart rate felt at an artery; a normal adult resting pulse is about 60 to 100 beats per minute.
Memory tipUnder 60 or over 100: report.
Respirations
Breaths per minute; one rise and fall of the chest is one breath. Normal for adults at rest is about 12 to 20.
Memory tipCount without the resident noticing.
Temperature sites
Rectal readings are usually highest, oral in the middle, and axillary (armpit) lowest. The average normal oral temperature is about 98.6°F (37°C).
Memory tipRecord the site you used.
Blood pressure
The force of blood in the arteries, written as systolic over diastolic. Normal for adults is below 120/80 mm Hg.
Memory tipSmall cuff = falsely high reading.
Source: American Heart Association blood pressure categories · as of 2026
Intake and output (I&O)
Measuring fluids taken in and given off. Fluids include anything liquid at room temperature; 1 ounce equals 30 mL.
Memory tipOunces × 30 = mL.
Observe and report
Noticing changes in a resident's condition and telling the nurse promptly, using facts and the resident's own words.
Memory tipSudden change → tell the nurse now.
Often tested
- Radial pulse: thumb side of the inner wrist, use fingertips.
- Count an irregular pulse for a full 60 seconds.
- Report the resident's own pain rating, even if they look comfortable.
- Weigh at the same time, same scale, same clothing.
Easy to confuse: Normal adult resting vital signs
| Vital sign | Normal range | Unit |
|---|---|---|
| Pulse | 60 to 100 | beats per minute |
| Respirations | 12 to 20 | breaths per minute |
| Oral temperature | About 98.6°F (37°C) on average | degrees |
| Blood pressure | Below 120/80 | mm Hg |
3 sample questions
Verified practice questions from this unit.
Question 1. What is the normal resting pulse rate for an adult?
- ① 60 to 100 beats per minute
- ② 100 to 140 beats per minute
- ③ 12 to 20 beats per minute
- ④ 40 to 60 beats per minute
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Answer: ① 60 to 100 beats per minute
Key point: Adult pulse 60–100; report outside this range
A normal adult resting pulse is 60 to 100 beats per minute. Report a pulse below 60 or above 100, or one that is irregular, unless the nurse has told you that it is normal for that resident.
Wrong choices
- 100 to 140 beats per minute: Above 100 at rest is fast (tachycardia).
- 12 to 20 beats per minute: 12 to 20 is the normal adult breathing rate, not the pulse.
- 40 to 60 beats per minute: Below 60 is slow (bradycardia) for most adults.
Question 2. What is the normal breathing (respiration) rate for an adult at rest?
- ① 12 to 20 breaths per minute
- ② 60 to 100 breaths per minute
- ③ 4 to 8 breaths per minute
- ④ 30 to 40 breaths per minute
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Answer: ① 12 to 20 breaths per minute
Key point: Adult respirations 12–20 per minute
A normal adult breathes about 12 to 20 times per minute at rest. Count one rise and one fall of the chest as one breath. Report breathing that is very fast, very slow, noisy, or labored.
Wrong choices
- 60 to 100 breaths per minute: 60 to 100 is the normal adult pulse range.
- 4 to 8 breaths per minute: This is far too slow for a healthy adult.
- 30 to 40 breaths per minute: This is far too fast for an adult at rest.
Question 3. A resident who is usually talkative is suddenly confused and sleepy. What should the aide do?
- ① Wait until tomorrow to see if it gets better
- ② Report it to the nurse right away
- ③ Tell the resident's roommate to keep an eye on her
- ④ Write it in the notes at the end of the shift
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Answer: ② Report it to the nurse right away
Key point: Sudden change in a resident: report right away
A sudden change in alertness, behavior, or ability can be a sign of a serious problem such as infection or stroke. Report changes to the nurse right away.
Wrong choices
- Wait until tomorrow to see if it gets better: Waiting can delay treatment for a serious problem.
- Tell the resident's roommate to keep an eye on her: The roommate is not responsible for her care, and this breaks privacy.
- Write it in the notes at the end of the shift: A sudden change needs to be reported now, not hours later.
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