A healthy adult’s heart rate during sleep typically falls between 40 and 60 beats per minute (bpm). That’s noticeably lower than the standard resting heart rate of 60 to 100 bpm you’d expect while awake and sitting quietly. This drop is normal and reflects your body shifting into recovery mode as your nervous system dials down stimulation to your heart and blood vessels.
Why Your Heart Rate Drops During Sleep
When you fall asleep, the branch of your nervous system responsible for rest and recovery takes over. This slows your heart rate, lowers your blood pressure, and relaxes your blood vessels. The deeper you sleep, the more pronounced this effect becomes. During deep sleep, your heart reaches its slowest, most stable rhythm of the night, with the calming side of your nervous system at peak influence.
REM sleep, the stage associated with vivid dreaming, is the exception. During REM, your nervous system becomes more active again, and your heart rate can fluctuate and speed up, sometimes approaching waking levels. This is why a nighttime heart rate graph from a wearable often looks like a series of dips and rises rather than a flat line. Those rises typically correspond to REM periods, which cycle roughly every 90 minutes throughout the night.
Sleeping Heart Rate by Age
Children have significantly faster heart rates than adults, both awake and asleep. While specific sleeping ranges aren’t as well defined for kids, their waking resting rates give a useful frame of reference, since sleep rates will fall below these numbers:
- Newborns (birth to 4 weeks): 100 to 205 bpm at rest
- Infants (4 weeks to 1 year): 100 to 180 bpm
- Toddlers (1 to 3 years): 98 to 140 bpm
- Preschool (3 to 5 years): 80 to 120 bpm
- School age (5 to 12 years): 75 to 118 bpm
- Adolescents (13 to 17 years): 60 to 100 bpm
- Adults (18+): 60 to 100 bpm
By adulthood, the expected sleeping range settles into that 40 to 60 bpm window. Older adults may see slightly higher or more variable nighttime rates due to age-related changes in heart rhythm regulation, but there isn’t a separate clinical range for seniors.
When a Low Sleeping Heart Rate Is Normal
Seeing your heart rate dip into the low 40s or even the upper 30s during sleep can be alarming if you’re checking a wearable device for the first time. But a heart rate below 60 bpm, which technically meets the definition of bradycardia, is common during sleep and isn’t automatically a problem. It’s especially typical in physically fit people and endurance athletes, whose hearts pump more blood per beat and simply don’t need to beat as often.
A study of athletes found that the minimum heart rate during sleep ranged from 36 to 65 bpm, with an average of about 53 bpm. Endurance training can lower resting heart rate by 3 to 7 bpm on average, and that reduction carries over into sleep. If you’re active and feel fine during the day, a sleeping heart rate in the upper 30s or low 40s is generally nothing to worry about.
What Raises Your Heart Rate at Night
Several common factors can push your sleeping heart rate above 60 bpm, sometimes significantly. Alcohol is one of the biggest offenders. In a controlled study comparing nights with and without alcohol, participants averaged 65 bpm during sleep after drinking, compared to 56 bpm on placebo nights. That’s roughly a 9 bpm increase, enough to keep your body in a mildly stressed state all night and potentially explain why sleep after drinking feels less restorative.
Other factors that elevate your nighttime heart rate include caffeine consumed later in the day, dehydration, high-sodium or high-sugar meals close to bedtime, and emotional stress or anxiety. Hormonal shifts during menopause and pregnancy also play a role. During pregnancy, resting heart rate increases by 10 to 20 bpm over the course of the trimesters, rising progressively to an average of about 91 bpm around week 34.
Sleep Apnea and Heart Rate Spikes
If you or a partner notice that your heart rate spikes repeatedly throughout the night, obstructive sleep apnea is one of the most important causes to consider. In sleep apnea, the airway collapses periodically during sleep, temporarily blocking airflow. Each time the airway reopens, the heart responds with a burst of speed, a reflex that begins within one second of the first open breath.
These heart rate spikes are graded: the more severe the airway obstruction, the larger the jump in heart rate when breathing resumes. This happens even without the person consciously waking up. The pattern of repeated drops and spikes puts chronic stress on the cardiovascular system, which is why untreated sleep apnea is linked to high blood pressure, irregular heart rhythms, and increased heart disease risk over time. A nighttime heart rate graph that looks like a jagged sawtooth, rather than a smooth U-shape, can be an early clue worth discussing with a doctor.
Night Palpitations and Sleep Position
Feeling your heart pound, flutter, or skip a beat when you lie down at night is remarkably common. These palpitations are often triggered by the same everyday factors that raise nighttime heart rate: caffeine, alcohol, stress, and hormonal changes. But sleep position itself can play a role. Lying on your left side or sleeping in a hunched position increases pressure inside the chest, which can make your heartbeat more noticeable or trigger brief rhythm irregularities.
Occasional palpitations at night are rarely dangerous. They become more significant if they happen frequently, last more than a few seconds, or come with lightheadedness, chest pain, or shortness of breath, which can point to an underlying rhythm disorder like atrial fibrillation.
Tracking Your Sleeping Heart Rate
Consumer wearables like smartwatches and ring-style trackers have become the most common way people discover their sleeping heart rate in the first place. These devices use light sensors on the skin to estimate heart rate, and for simple overnight averages, they tend to be reasonably accurate. Where they’re less reliable is in capturing brief rhythm irregularities or providing precise beat-to-beat variability data, which still requires medical-grade equipment.
The most useful thing you can do with wearable data is track your own trend over time rather than fixating on a single night’s reading. A consistent sleeping heart rate that suddenly rises by 5 to 10 bpm and stays elevated for days may signal illness, overtraining, poor recovery, or increased stress, even before you feel symptoms. Conversely, a gradual decrease in your average sleeping heart rate as you get fitter is a reliable sign that your cardiovascular system is adapting well to training.
If your sleeping heart rate consistently runs above 60 bpm, you’re not necessarily in trouble, but it’s worth considering whether alcohol, stress, medications, or an underlying condition like sleep apnea might be contributing. A rate that regularly exceeds 100 bpm during sleep, or one that drops below 30 bpm with daytime symptoms like fatigue or dizziness, warrants a closer look with a medical evaluation.