The Nature of Sleep Cycles

Adults typically go through a series of sleep cycles that last around 90 minutes each. The night usually begins with lighter sleep stages, followed by deeper sleep, and ends with rapid eye movement (REM) sleep, which is often linked to vivid dreams. A healthy sleep pattern involves more deep sleep in the first half of the night and more REM sleep in the second half. On average, adults experience five or six sleep cycles per night. It is normal to briefly wake up at the end of each cycle, amounting to five awakenings each night. These awakenings may become more frequent with age but remain a natural part of sleep.

What Defines Quality Sleep?

While adults are advised to sleep seven to nine hours a night, good sleep quality is defined by more than just duration. Quality sleep is characterized by falling asleep within 30 minutes, experiencing minimal prolonged awakenings, and waking up feeling refreshed. Persistent daytime sleepiness, despite getting enough sleep, may indicate an underlying problem. Needing naps or feeling unrefreshed could signal a sleep disorder that might require consulting a healthcare professional.

Common Sleep Issues

Sleep disorders like insomnia and sleep apnea are also quite common. Insomnia, which affects 25% of adults, involves difficulty falling or staying asleep. Sleep apnea, characterized by pauses in breathing during sleep, becomes more prevalent with age. Up to 40% of middle-aged adults may experience it. Chronic health issues, medications, or external factors such as noise can also disrupt sleep. If frequent awakenings cause frustration or interfere with daytime functioning, consulting a sleep specialist is advisable.

Can Wearable Sleep Trackers Help?

Sleep-tracking devices, such as smartwatches, offer insights into sleep stages, but their accuracy can vary. While they provide general estimates, they are not as precise as in-laboratory polysomnography (PSG), which remains the gold standard for assessing sleep. PSG examines breathing, brain activity, heart rate, and oxygen levels during sleep. 

Rather than focusing on nightly sleep data from trackers, it may be more beneficial to observe overall sleep patterns, such as bedtime and wake-up times over a period. Recognizing these patterns can help identify behaviors that negatively impact sleep, like irregular routines or a disruptive sleeping environment. 

If reviewing sleep data leads to increased anxiety, it may not be useful to continue tracking. It is always advisable to discuss sleep concerns with a healthcare provider, who can refer individuals to the appropriate sleep health specialist if necessary.

(This article is a reworked version of a PTI feed)