The heart rate observed during sleep is a direct indicator of cardiovascular health and the state of the autonomic nervous system. Unlike the daytime rate, the nocturnal rate reflects a period when the body is in a state of rest and recovery, free from the stresses of daily activity. Monitoring this rate provides insight into how efficiently your heart works when the body’s demands are lowest. The number of beats per minute naturally slows down significantly as the body shifts into repair mode.
Defining Resting and Sleeping Heart Rate
It is helpful to distinguish between Resting Heart Rate (RHR) and Sleeping Heart Rate (SHR) as they represent different physiological states. RHR is the number of times your heart beats per minute when you are awake, calm, and inactive, typically measured first thing in the morning. For most healthy adults, this rate falls between 60 and 100 beats per minute (BPM).
Sleeping Heart Rate is the lowest rate your heart achieves during a full night of sleep, often reaching its minimum during deep sleep stages. This rate is usually lower than RHR because the parasympathetic nervous system, the body’s “rest and digest” control, becomes dominant. The heart rate during sleep may be 10 to 30 percent lower than the average daytime RHR, indicating increased efficiency.
The drop in heart rate during sleep is a healthy sign that the cardiovascular system is receiving a necessary period of recovery. This nocturnal dipping allows the heart to work less, which benefits long-term heart health. SHR provides a measurement less influenced by temporary factors like anxiety, posture, or recent physical movement.
Normal Heart Rate Ranges by Age
A healthy sleeping heart rate varies considerably across the lifespan, starting much higher in infancy and gradually decreasing into adulthood. The heart rate stabilizes as the body matures and the circulatory system becomes more efficient. These ranges represent typical beats per minute (BPM) for a person in good health.
Infants and Young Children
Infants (0–1 year) have the fastest heart rates, with a normal sleeping range between 80 and 160 BPM. This higher rate meets the metabolic demands of rapid growth and smaller heart size. Toddlers and Young Children (1–6 years) see a slight decrease, with a typical range of 80 to 120 BPM.
Older Children and Teens
As children grow, their hearts become more efficient, leading to a reduction in the average rate. Older Children (6–18 years) generally have a sleeping heart rate range from 60 to 110 BPM. By the teenage years, the rate begins to resemble the adult range, often stabilizing between 60 and 100 BPM.
Adults and Seniors
For most Adults (18–65 years), a normal sleeping heart rate is between 40 and 60 BPM. Highly fit individuals, such as trained athletes, may consistently see rates as low as 40 BPM, reflecting superior cardiovascular conditioning. Seniors (65+ years) typically maintain a range similar to younger adults, often between 50 and 85 BPM, though individual variation can be wider due to other health factors.
Common Factors That Influence Your Rate
Several non-pathological factors can cause a person’s sleeping heart rate to fluctuate or fall outside the middle of the normal range. Physical fitness level is a significant influence; regular aerobic exercise strengthens the heart muscle, allowing it to pump more blood with fewer beats. This enhanced efficiency results in a naturally lower rate, meaning a well-conditioned person’s heart does not need to work as hard during sleep.
The current sleep stage is a major factor causing nocturnal fluctuations, as the heart rate is dynamic throughout the night. The rate drops to its lowest point during deep, non-REM sleep stages, reflecting the greatest degree of physical rest. Conversely, the heart rate can temporarily rise and become more variable during REM sleep, a stage characterized by dreaming and increased brain activity.
External and temporary factors also play a role in nightly heart rate variation. Consuming caffeine or alcohol close to bedtime can elevate the heart rate, as these substances act as stimulants or disrupt sleep architecture. Certain medications, such as beta-blockers, are designed to slow the heart rate and contribute to a lower SHR. Even a room temperature that is too warm can prevent the heart rate from dipping to its usual low, as the body works harder to regulate temperature.
Recognizing Signs of Deviation
When the sleeping heart rate consistently falls outside the established normal range for an adult, it may indicate a need for medical consultation. A consistently high rate, known as nocturnal tachycardia, is generally defined as staying above 100 BPM during sleep. This can signal that the body is under strain due to factors like chronic stress, dehydration, or an underlying medical condition such as a thyroid disorder.
If the rate remains elevated, a person might experience symptoms such as heart palpitations, a racing heart, or shortness of breath. A heart rate that consistently remains too low, known as bradycardia, is typically considered a dip below 40 BPM for an adult. While common in athletes, a low rate accompanied by symptoms like lightheadedness, chronic fatigue, or fainting could signal a conduction disorder or heart block.
Persistent deviation from a healthy range, especially when accompanied by noticeable symptoms, warrants evaluation by a healthcare provider. Issues like obstructive sleep apnea, where breathing interruptions cause repeated stress on the heart, or undiagnosed electrical abnormalities can manifest as an abnormal sleeping heart rate. A medical professional can assess the rate in the context of overall health and determine if the deviation is physiological or a sign of an underlying health concern.