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Declining Sleep Quality and the Conditions Needed for Better Rest

• Koreans sleep 18% less than the OECD average
• Only 7% of people achieve truly restful sleep
• “Recognizing the root cause of stress is the first step”

Koreans have long struggled with insufficient sleep. Although the issue has been discussed for decades, there has been little sign of improvement. According to the “2024 Sleep Status Report of Koreans” presented at a recent symposium by the Korean Sleep Research Society, the average Korean adult sleeps 6 hours and 58 minutes per day, which is 18% shorter than the OECD average.

This is not a new problem. In OECD statistics from 2015, Korea already ranked last among 18 surveyed countries in terms of average sleep duration. Looking further back, Koreans have rarely, if ever, had above-average sleep times compared with other countries.

According to the report, 60% of respondents said they experienced sleep-related problems. The number of patients seeking medical treatment for insomnia and other sleep disorders reached 678,000 in 2024, more than double the 278,000 recorded in 2010.

One of the most concerning issues is sleep quality. Only 7% of Koreans reported getting adequate restorative sleep, far below the global average of 13%. The report concluded that Koreans are not only sleeping fewer hours but are also experiencing declining sleep efficiency.

Sleep quality is not determined simply by the number of hours spent asleep. It is also closely related to how deeply and effectively a person sleeps. Sleep efficiency refers to the percentage of time spent in bed that is actually spent sleeping. Time spent lying awake before falling asleep, waking up during the night, or waking earlier than planned all affect this measurement.

An analysis conducted by Samsung Electronics and the Korean Sleep Research Society using 716 million sleep records collected through the Samsung Health app between June 2021 and May 2023 showed that both sleep duration and overall sleep scores continued to decline, along with reduced sleep efficiency.

A separate 2025 Sleep Habits, Behaviors, and Sleep Apnea Awareness Survey conducted by Philips Korea and Korea Research among 2,000 Korean adults found that only 29.5% of respondents were satisfied with their sleep, a significant drop from 40% in the 2019 survey.

Professor Joo Eun-yeon, a neurologist at Samsung Seoul Hospital, warned:
“Lack of sleep affects not only immunity, obesity, and cardiovascular health but also brain and mental health, including cognitive function, mood disorders, and overall quality of life.”

 

Stress: The Biggest Enemy of Good Sleep

The report identified psychological stress as the leading cause disrupting sleep, affecting 62.5% of respondents. For many Koreans, poor sleep is closely connected to the stress they experience in daily life.

Other factors included:

• Physical fatigue (49.8%)
• Poor metabolism (29.7%)
• Noise from neighbors or outside environments (19.4%)
• Physical pain (19.2%)

So how can stress be managed?

British psychologist Dr. Julie Smith emphasizes that the first step in stress management is “recognizing and becoming aware of it.”

Dr. Smith, who has more than 10 million followers across social media platforms such as TikTok and YouTube, explains:
“Although the reasons people experience stress vary, stress often peaks when people feel they cannot handle what is coming next.”

When the brain remains in a heightened state of anxiety, sleep quality can decline, leading to fatigue, anxiety, difficulty concentrating, and weakened immunity.

Dr. Smith also points out that many people fail to recognize their own stress levels. She suggests that wearable devices can be useful tools for monitoring stress patterns.

Devices such as the Samsung Galaxy Watch, Apple Watch, Fitbit, and Garmin track heart rate, activity levels, and sleep patterns, with some models also offering stress monitoring features.

These devices estimate stress levels based on heart rate variability (HRV), which measures changes in the time intervals between heartbeats and reflects activity in the autonomic nervous system. Generally, higher stress levels are associated with lower HRV.

However, wearable stress measurements are not yet perfectly accurate. Studies suggest that smartwatch-based stress detection accuracy ranges from 52% to 70%, meaning they should be considered a helpful reference rather than a definitive diagnosis.

 

New Technologies for Measuring Stress

Various new stress-monitoring technologies are also emerging.

A research team led by Professor Kim Jung-hyun from the Department of Psychiatry at Seoul National University Bundang Hospital, in collaboration with the Seoul National University Institute of New Media and Communications, developed an AI-based stress measurement technology using voice analysis.

The system analyzes changes in vocal tone, muscle tension, and breathing patterns, achieving approximately 70% accuracy.

Professor Kim explained:
“If people could regularly check their stress levels through smartphones, they could more easily practice coping strategies such as meditation and exercise or seek professional help when necessary.”

 

Sleep Is the Key to Managing Stress

Ironically, the most effective way to manage stress is often to improve sleep first.

However, when achieving quality sleep is difficult, additional efforts are necessary, including:

• Regular exercise
• Relaxation techniques
• Improving sleep habits and routines

As interest in the sleep industry grows, various digital solutions designed to improve insomnia are becoming available. However, user satisfaction remains limited.

Among people with insufficient sleep, 49.5% said digital sleep tools were not helpful, while 60.5% of those with sleep disorders reported the same. Many users eventually stopped using these services.

Experts say that while digital devices have improved significantly in terms of sleep tracking and evaluation, they still lack the ability to effectively encourage real behavioral changes that improve sleep quality.

Professor Kim Hye-yoon, a neurologist at Catholic Kwandong University, noted:
“Future digital sleep solutions need a more detailed understanding of users’ actual needs.”

 

Digital Therapeutics: A Promising but Expensive Solution

Recently approved digital therapeutics for sleep disorders have also attracted attention.

In Korea, Somzz by Aimmed and WELT-I by WELT received approval from the Ministry of Food and Drug Safety in 2023. Unlike simple sleep-tracking tools, these treatments aim to actively change patients’ behaviors and habits.

However, high costs remain a barrier. Monthly prescription fees can reach 250,000 won, creating a significant financial burden for patients.

Despite the growing number of people experiencing sleep problems, many still do not seek professional help.

The survey found that 64% of respondents had never received medical assistance for sleep problems, and only 25% had consulted a sleep specialist, which is about half of the global average of 50%.

Professor Jeon Jin-sun, a neurologist at Hallym University Kangnam Sacred Heart Hospital, stated:

“Although interest in sleep is increasing, many people still consider sleep disorders minor issues and do not take them seriously. As a result, research and policy support for sleep disorders remain insufficient compared with other diseases such as cardiovascular disease and cancer.”

She added:
“Insurance coverage for some sleep disorder treatments remains limited. In some cases, global pharmaceutical companies have even withdrawn certain treatments from the Korean market due to low drug prices, leaving patients with conditions such as narcolepsy without adequate treatment options.”

Conclusion: Better sleep and stress management are not separate issues. They are deeply connected. Reducing stress can improve sleep, and improving sleep can make the body and brain more resilient against stress. Creating healthy sleep habits may be the most important first step toward breaking the cycle.

Source: 한겨례 (https://www.hani.co.kr/arti/hanihealth/healthlife/1187863.html)