Respiratory rate during sleep: what is normal and what do Apple Watch readings mean?

Around 12 to 20 breaths per minute is a commonly used reference range for adults at rest. Sleep breathing varies, so this is not a strict overnight safety threshold. Breathing changes with sleep stage, and a smartwatch’s lowest recorded value is different from your average across the night. Your usual pattern and any symptoms also matter.

Apple Watch readings can help you notice changes worth discussing with a doctor. A respiratory rate reading alone cannot diagnose or rule out sleep apnoea.

This guide focuses on adults. Children need age-specific assessment.

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What is respiratory rate, and what does brpm mean?

Respiratory rate means the number of breaths you take in one minute. One breath consists of breathing in and breathing out.

Brpm means breaths per minute. A reading of 16 brpm means approximately 16 complete breaths each minute. You may also see respiratory rate shortened to RR or resp rate.

Breathing rate, respiration rate and breathing frequency generally describe the same measurement. “Respiratory level” is less precise: check whether your app is showing breaths per minute or blood oxygen.

Measurement	What it describes	Unit
Respiratory rate	How frequently you breathe	Breaths per minute
Heart rate	How frequently your heart beats	Beats per minute
Oxygen saturation, or SpO₂	The percentage of haemoglobin carrying oxygen	%

These measurements answer different questions. A normal breathing rate does not, by itself, establish that oxygen levels or airflow are normal.

What is a normal respiratory rate while sleeping?

The commonly used adult resting respiratory rate reference range is 12 to 20 breaths per minute. This provides a useful starting point for interpreting sleep readings, but resting clinical measurements and overnight wearable estimates are not interchangeable.

During non-REM sleep, breathing generally becomes steadier. During REM sleep, when vivid dreaming commonly occurs, breathing can become more variable. A brief increase or decrease therefore needs context.

When reviewing your sleep respiratory rate, consider:

• Your usual readings: Is this typical for you or a clear change?
• The type of value: Is it a minimum, maximum, individual sample or average?
• Persistence: Was it one unusual recording or a repeated pattern?
• Symptoms: Are there breathing pauses, gasping, breathlessness or daytime sleepiness?

For example, a change from your usual 13 to 15 brpm to 18 to 20 brpm over several nights may deserve attention, particularly if you feel unwell, even though both fall within the broad adult reference range.

Equally, one low point on a graph does not establish that you breathed at that rate throughout the night.

What does Apple Watch actually measure?

Apple Watch uses its accelerometer, a movement sensor, to estimate respiratory rate while you sleep. It does not directly measure airflow through your nose and mouth in the way that a respiratory sleep study can.

Where to find your sleeping respiratory rate

On your iPhone:

1. Open Health.
2. Tap Browse, then Respiratory.
3. Select Respiratory Rate.
4. Open Show More Respiratory Rate Data to explore the available information.

Apple’s guide to reviewing sleeping respiratory rate explains that the Sleep entry shows the range recorded during sleep. Apple also states that respiratory rate measurements are not intended for medical diagnosis or treatment.

How to interpret the graph

Check what the displayed number represents before comparing it with a reference range.

An overnight range of 9 to 19 brpm means the recorded estimates varied. It does not mean your average was 9, or that you spent a particular amount of time at either end of the range.

A decimal, such as 14.6 brpm, reflects how the rate is calculated or summarised. It does not mean you took a fraction of a physical breath.

If readings seem inconsistent, check that sleep tracking is enabled and the watch fits securely and comfortably. A loose fit can affect the quality of the readings.

What does “outside your typical range” mean?

The Vitals app establishes a personal range from your recorded health metrics. A result outside that range means it differs from your usual measurements.

Your personal “typical range” is not a medical diagnosis or a guarantee of healthy breathing. Apple’s Vitals notifications consider changes across multiple metrics, and symptoms still need attention even when no notification appears.

Are Apple Watch respiratory rate and sleep apnoea notifications the same?

No. Respiratory Rate and Breathing Disturbances are separate measurements.

Respiratory Rate estimates how often you breathe. On compatible watches, Breathing Disturbances looks for movement patterns associated with interruptions to normal breathing during sleep.

Apple’s sleep apnoea notifications guidance explains that:

• The feature looks for patterns suggesting moderate to severe sleep apnoea.
• It requires at least 10 nights of wear within a 30-day period.
• It is intended for adults aged 18 or over who have not already been diagnosed with sleep apnoea.
• A notification should prompt a discussion with a doctor.
• Some people with sleep apnoea will not receive a notification.

The feature cannot confirm a diagnosis or monitor how well prescribed sleep apnoea treatment is working. If you receive an alert, you can export a report to share with your clinician.

Do not wait for a watch notification if someone has noticed repeated breathing pauses or you regularly wake gasping.

What causes a high respiratory rate while sleeping?

A high breathing rate during sleep can have several explanations. A watch reading cannot identify which one applies.

Possible causes include:

• Fever or respiratory infection: Illness can increase breathing rate, particularly alongside cough or feeling unwell.
• Asthma or COPD symptoms: Worsening airflow obstruction can affect breathing overnight.
• Disrupted breathing during sleep: Sleep apnoea can cause pauses followed by a brief arousal and faster breathing.
• Heart problems: Breathlessness when lying down, especially with ankle swelling, needs assessment.
• Temporary sleep-related variation: Breathing may become faster or less regular during REM sleep.

Persistent changes are more informative than a single peak. Repeated fast breathing with cough, wheeze, fever or breathlessness should be discussed with a clinician.

Does heavy or loud breathing mean a high respiratory rate?

Not necessarily. Fast breathing describes frequency. Heavy breathing may describe depth or effort. Loud breathing describes sound, including snoring. Someone can snore loudly without breathing especially quickly.

However, loud snoring accompanied by pauses, choking or daytime sleepiness may indicate sleep apnoea. Our guide to why you snore and when to seek assessment explains this distinction.

What causes a low respiratory rate while sleeping?

A low overnight estimate can reflect sleep-related variation or an imperfect recording. Persistent slow breathing can also be associated with medicines or medical conditions.

Possible causes include opioid painkillers, certain sedating medicines, heavy alcohol use, a severely underactive thyroid and conditions affecting the brain’s control of breathing.

The medical term for abnormally slow breathing is bradypnoea. Whether a reading represents bradypnoea depends on the person’s age, circumstances and how it was measured.

Do not assume a very low number proves excellent fitness. Repeated low readings, particularly with morning headaches, unusual sleepiness or breathing pauses, warrant medical advice.

Slow or shallow breathing with difficulty waking someone is an emergency, especially after opioids, sedatives or alcohol. Call 999.

If prescribed medicines may be contributing, contact the prescriber rather than changing the dose yourself.

What should you do about an unusual overnight reading?

1. Check how you feel now

Current breathing difficulty takes priority over the graph. Do not delay seeking help while collecting more watch data.

2. Check the reading in context

Review the surrounding nights and establish whether you are looking at an average or an extreme value. Note recent illness, medication changes, alcohol use and any symptoms.

An unexplained pattern is more useful to discuss than an isolated screenshot without dates or context.

3. Check your current resting breathing rate if appropriate

If you feel well enough, sit quietly for several minutes. Ask someone to count your chest or abdomen rising over a full 60 seconds, while you breathe naturally. One complete rise and fall counts as one breath.

This measures your breathing now. A normal awake count cannot confirm what happened overnight or exclude sleep apnoea.

4. Arrange assessment when changes persist

Speak to your GP or respiratory specialist if readings remain unusually high or low, or if you have snoring with breathing pauses, waking gasping, persistent morning headaches or excessive daytime sleepiness.

Bring your medication list, relevant screenshots and any observations from your partner.

When should you seek urgent help?

Call 999 if you have:

• Severe breathing difficulty, including struggling to speak.
• A tight or heavy chest, or pain spreading to your arm, back, neck or jaw.
• Lips or skin becoming very pale, blue or grey.
• Sudden confusion.

Also call 999 if someone is difficult to wake and their breathing is slow, shallow or abnormal.

For new or worsening breathlessness without these emergency features, seek urgent advice through NHS 111. Follow the NHS advice on shortness of breath. A normal watch reading should never delay help for concerning symptoms.

When is a sleep study needed?

A sleep study may be appropriate when symptoms suggest obstructive sleep apnoea, including:

• Repeated breathing pauses witnessed by another person.
• Waking with choking or gasping.
• Loud snoring alongside unrefreshing sleep or daytime sleepiness.
• An Apple Watch sleep apnoea notification requiring clinical assessment.

For suspected obstructive sleep apnoea in adults, NICE recommends home respiratory polygraphy. This records breathing overnight using dedicated equipment. Further testing may be needed if an initial test is negative but significant symptoms remain.

A sleep assessment examines interruptions to breathing and their consequences. An average breaths-per-minute figure cannot provide the same information.

If the main problem is breathlessness, cough or wheeze, investigations may instead include lung function testing, blood tests or imaging, depending on the assessment.

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