How to Read a Patient Monitor at the Hospital

Certified Registered Nurse Anesthetist Christina Massaro explains what to look for on a hospital monitor

Co-authored by Jennifer Mueller, JD Medically reviewed by Christina Massaro

Last Updated: December 22, 2025 Fact Checked

When you visit a loved one in the hospital, you're likely to find your eye drawn to the monitor at their bedside. If you're wondering what all those wavy lines, numbers, and abbreviations mean, you've come to the right place! Read on to learn how to read and understand the patient monitor so you'll know what all those values can tell you about your loved one's condition. And if you have any questions or concerns, don't hesitate to ask a doctor or nurse on duty.

Common Information on a Hospital Monitor

Certified Registered Nurse Anesthetist Christina Massaro says every monitor is different, but you will generally see the following information:

A green line with intermittent squiggles and a flashing number represents the heart rate and rhythm.
The white waveform represents respiratory rate.
The blue waveform is the pulse oximeter, which tracks blood oxygen levels. A good level is 90% or higher.
You'll also see a pair of numbers representing the patient's systolic and diastolic blood pressure.

1

Pulse rate (PR)

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A normal resting pulse rate is between 60 and 100 beats per minute. This number is typically in the top right-hand corner of the monitor screen and tells you how fast the patient's heart is beating. The number might go up when the patient sits up, talks, or moves around.^{[1]
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- Someone who is injured or ill is likely to have a higher resting pulse rate than normal, but this is usually no cause for alarm. The monitor will issue an alert if the number gets too high.
- Athletes who do a lot of cardiovascular training, such as cyclists or long-distance runners, might have a normal resting pulse rate of around 40 beats per minute.^{[2]
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2

Body temperature (TEMP)

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The normal temperature range for adults is 97.8 to 99 °F (36.6 to 37.2 °C). This is typically the second number you'll see on a patient monitor, directly under the pulse rate. A body temperature over 99 °F (37 °C) is considered a fever, while anything below 95 °F (35 °C) is considered hypothermia.^{[3]
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- It's normal for a patient's body temperature to go up a degree or so if they're eating or active. Their temperature might also go down a degree or two if they're sleeping.^{[4]
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3

Blood-oxygen level (SpO2)

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Normal oxygen levels are between 95 and 100. This number is a percentage that tells you how much oxygen is in the patient's blood. Even a little below 95 is usually okay, but the patient might require supplemental oxygen if the number drops below 90.^{[5]
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- Oxygen saturation is typically monitored using a pulse oximeter, a small clip on the patient's finger or toe.
- The SpO2 number isn't always displayed on a patient monitor, but you'll usually see it if the patient is experiencing a respiratory condition, such as pneumonia or COVID-19.

4

Respiration rate (RR)

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The normal respiration rate for adults at rest is 12-16 breaths per minute. Quite simply, this is the number of breaths the patient takes in one minute. A patient's respiration rate typically increases if they have a fever and might not be any cause for alarm. However, you do want to make sure the patient isn't having any difficulty breathing.^{[6]
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- If the patient seems to be having trouble breathing, such as if they're gasping for breath or breathing very shallowly, press the call button to have a nurse come and evaluate their condition.

5

Systolic blood pressure (SYST)

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Normal systolic blood pressure is between 90-120 mm Hg. This number, together with the diastolic blood pressure number, is typically found in the bottom-right corner of the screen. Systolic blood pressure tells you the amount of force exerted on the patient's arteries at the moment when their heart is beating.^{[7]
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Go to source} High blood pressure occurs with systolic blood pressure of 140 mm Hg or greater.^{[8]
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- A patient's systolic blood pressure is read together with their diastolic blood pressure—even though the numbers might appear separately, they're expressed as a single unit.

6

Diastolic blood pressure (DIAS)

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Normal diastolic blood pressure is between 60-80 mm Hg. Diastolic blood pressure is the force exerted on the patient's arteries between heartbeats, or when their heart is at rest.^{[9]
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Go to source} High blood pressure occurs with diastolic blood pressure of 90 mm Hg or greater.^{[10]
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- When you read a patient's blood pressure, express it as a ratio with the systolic blood pressure over the diastolic blood pressure. For example, if the monitor showed systolic blood pressure of 110 and diastolic blood pressure of 75, you'd say the patient's blood pressure is "110 over 75."^{[11]
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7

ECG waveform

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An electrocardiogram (ECG) records the electrical activity of the heart. This is usually the top wavy line on the hospital monitor. You can think of it as an image of the pulse rate, which is displayed right next to it. Healthcare practitioners study extensively to learn how to read and interpret an ECG waveform. As the loved one of a patient, all you really need to know is that each spike or peak corresponds to a heartbeat. If the patient has a regular heartbeat, these spikes will occur the same number of little blocks apart from each other.^{[12]
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- The ECG on a patient's hospital monitor typically comes from lead II, electrodes attached to the patient's right arm and left leg. If the ECG shows any irregularities, doctors or nurses will confirm the issue by attaching additional leads.

8

SpO2 waveform

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Use the SpO2 waveform to monitor the patient's blood flow. The SpO2 waveform is the wavy line under the ECG waveform, usually blue but sometimes red. As long as each crest on the SpO2 waveform matches up with a spike on the ECG right above it, you can rest assured that oxygenated blood is circulating efficiently with each heartbeat.^{[13]
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- Like the ECG, healthcare professionals undergo a lot of training to learn how to interpret these waveforms. It helps them see how well the heart is pumping blood, particularly to the patient's extremities.

9

Respiration waveform

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The respiration waveform shows how well the patient is breathing. Most patient monitors don't have a respiration waveform, but it'll be there if they have respiratory issues. This is the wavy line at the bottom of the screen and is usually yellow or white.^{[14]
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- Doctors and nurses use this waveform to identify apnea (when the patient suddenly stops breathing) or dyspnea (when the patient has difficulty breathing).

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Tips

Visiting a loved one in the hospital can be an overwhelming experience. Remember to take breaks to recharge. Most hospitals also have counseling services available if you need to talk to someone.^{[15]
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Warnings

Avoid focusing too much on a single number. Doctors and nurses will look at the vital signs together and take the context into consideration. A single number out of normal range usually isn't cause for concern.

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If the monitor or another piece of equipment starts beeping, call a nurse to come and check it out.^{[16]
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