Vital Signs & Normal Values

1Why vitals matter

Everything else in your assessment is interpretation. Vital signs are objective data — two EMTs taking the same set on the same patient should get the same numbers. That's what makes them worth radioing ahead, writing on a triage tag, and defending on a run report.

But a single set of vitals is only a snapshot. A pulse of 104 could be a healthy adult who just climbed a hill — or the first hour of hemorrhagic shock. You can't tell from one reading. Take a baseline set early, then repeat: every 15 minutes for a stable patient, every 5 minutes for an unstable one, and after every intervention. Serial sets turn snapshots into a story: pulse climbing, pressure sliding, respirations creeping up — that's a patient compensating, and losing.

2Normal ranges by age

This is the table to memorize. The pattern helps: as patients get younger, pulse and respiratory rates go up. A resting heart rate of 140 is an emergency in a 40-year-old and a normal Tuesday for a 4-month-old.

One pediatric fact matters more than any single row of that table: kids compensate, then crash. A child's cardiovascular system holds blood pressure near normal through vasoconstriction and tachycardia long after an adult would be visibly hypotensive — and then decompensates suddenly. Hypotension in a child is a late, ominous finding. If a pediatric blood pressure is low, that child is already deep into shock; don't wait for it to make the call.

3Pulse

The pulse is a pressure wave you can feel wherever an artery runs near the skin. Your workhorse sites:

• Radial — thumb side of the wrist. Default site for a conscious patient; feeling it also tells you the arm is perfusing.
• Carotid — side of the neck, in the groove beside the trachea. Use it on unresponsive patients; never press both sides at once.
• Brachial — inside of the upper arm. The pulse-check site for infants, whose necks are too short and wrists too small to palpate reliably.

Count for 30 seconds and double it (count a full 60 if the rhythm is irregular). You're recording three things:

At the EMT level, interpret rate in context. Tachycardia (adult pulse over 100) can be pain, fear, fever, or exertion — but it's also the body's first response to blood loss and shock, so a fast pulse that stays fast or keeps climbing deserves suspicion. Bradycardia (adult pulse under 60) can be normal in a fit athlete, but in a sick patient think hypoxia (especially in children, who go bradycardic when oxygen runs out), head injury, or cardiac problems. A slow pulse in a child is a pre-arrest sign until proven otherwise.

4Respirations

Respirations are the vital sign patients change just by knowing you're watching. The fix is a small deception: keep your fingers on the wrist after you finish the pulse and count breaths while the patient thinks you're still counting heartbeats. Watch or feel the chest rise; count for 30 seconds and double it.

As with pulse, record rate, rhythm, and quality — regular or irregular, and breathing that's easy and quiet versus labored, noisy, or shallow.

Adequate vs. inadequate breathing

A rate inside the normal range does not by itself mean breathing is adequate. Adequate breathing needs all three:

• Rate within the age-appropriate range;
• Tidal volume — full, even chest rise, not shallow sips of air;
• Effort — quiet and comfortable, not a workout.

A patient breathing 16 times a minute with barely visible chest rise is moving almost no air. Signs the work of breathing is failing: accessory muscle use (neck and shoulder muscles hauling the chest up), retractions (skin sucking in between the ribs, above the collarbones, or below the sternum — especially visible in kids), tripoding (sitting upright, leaning on the hands, chin thrust forward), nasal flaring, and one- or two-word sentences. Inadequate breathing gets ventilated, not just monitored.

Two abnormal patterns worth recognizing by name: agonal respirations — slow, gasping, ineffective breaths in a dying patient; treat as respiratory arrest, not "breathing" — and Cheyne-Stokes respirations — breaths that cycle deeper and faster, then taper off into a pause, then start again, often associated with brain injury. At the EMT level, name the pattern, support ventilation as needed, and transport; diagnosing the cause isn't your job.

5Blood pressure, skin & pupils

Blood pressure

Two methods with the same cuff:

• Auscultation — cuff plus stethoscope over the brachial artery. Inflate, bleed pressure off slowly, note the pressure where beats appear (systolic) and where they disappear (diastolic). This is the standard method.
• Palpation — for scenes too loud for a stethoscope. Keep your fingers on the radial pulse, inflate until it vanishes, deflate until it returns: that pressure is the systolic. Palpation gives you systolic only — record it as, for example, 110/P.

Use a cuff that fits: it should cover about two-thirds of the upper arm. Too small reads falsely high; too large reads falsely low. And remember the pediatric warning from Section 2 — in small children, skin signs and mental status will tell you about perfusion long before the blood pressure does.

Skin: color, temperature, condition

Skin is a free, instant perfusion monitor — when the body is in trouble, it shunts blood away from the skin first.

Capillary refill: squeeze a nail bed, release, and count until color returns. Under 2 seconds is normal — most reliable in children under 6, where it's a standard perfusion check. In adults it's less dependable (cold, age, and smoking all slow it), so treat it as one data point, not a verdict.

Pupils

The finding you want is PERRL — Pupils Equal, Round, Reactive to Light. Shine a light in each eye and watch for brisk, equal constriction. Deviations worth knowing at the EMT level:

• Unequal pupils — in a patient with altered mental status, think brain injury or rising intracranial pressure. (A small slice of the population has harmlessly unequal pupils — ask, and trend it.)
• Pinpoint pupils — classic for opioid overdose.
• Dilated, sluggish, or fixed pupils — hypoxia, severe brain injury, cardiac arrest, or stimulant drugs.

6Pulse oximetry & the Glasgow Coma Scale

Pulse oximetry

The pulse oximeter reads the percentage of hemoglobin carrying oxygen. For most patients your goal is an SpO₂ of 94% or higher; titrate oxygen to reach it rather than reflexively cranking a non-rebreather on everyone. Treat the number as one vital sign among many — a comfortable patient at 93% and a gasping patient at 96% are not sorted by the oximeter.

Know when the machine lies. Anything that weakens the signal skews the reading: poor perfusion and shock, cold fingers, nail polish, bright ambient light, and patient movement.

Glasgow Coma Scale

The GCS turns mental status into a number you can trend and hand off. Score the patient's best response in each category and add the three: the range is 3 (deep coma) to 15 (fully alert).

Report the components, not just the total — "GCS 12: E3, V4, M5" tells the hospital far more than "GCS 12." And as with every vital in this guide, a falling GCS matters more than any single score.

7Self-check

Answer before you expand. If you miss one, re-read that section — then go drill it for real.