A new study by Hengshui People’s Hospital, China, has found a strong link between late-night video viewing and essential hypertension (high blood pressure) among young and middle-aged adults.
Published Jan 12, 2025 | 7:00 AM ⚊ Updated Jan 12, 2025 | 7:00 AM
The longer people spend watching videos at bedtime, the higher their risk of developing hypertension.
Many unwind after a long day by scrolling through short videos on their smartphones before bed. However, what feels like a harmless way to relax might be negatively impacting health and even leading to serious conditions, including cardiac ailments.
A new study by Hengshui People’s Hospital has found a strong link between late-night video viewing and essential hypertension (high blood pressure) among young and middle-aged adults.
The research, conducted between January and September 2023, analysed data from more than 4,000 individuals. It revealed a startling trend: the longer people spent watching videos at bedtime, the higher their risk of developing hypertension.
Indian doctors concur and report seeing an increasing number of young patients with hypertension. They attribute this rise to lifestyle choices, poor eating habits, and disrupted sleep cycles.
The study found that the longer people watch short videos at bedtime, the higher their risk of developing high blood pressure. Researchers grouped participants based on their screen time, ranging from zero to more than four hours.
Those who watched videos for over four hours faced a staggering 40 times greater risk of hypertension compared to those who didn’t.
“This is not just about the screen time itself,” the authors said. “Late-night video habits lead to sedentary behaviour, poor sleep quality, and increased sympathetic nervous activity, all of which can raise blood pressure.”
Doctors in India agree but say it’s not just screens causing the problem. The study pointed to other factors behind hypertension, such as high-sodium diets, obesity, lack of exercise, diabetes, and family history.
Encouragingly, the study also found that adequate sleep, physical activity, and balanced diets can reduce the risk.
“Our research shows the importance of lifestyle changes,” said Dr Shangyu Liu, one of the authors. “Reducing screen time, especially before bed, is a simple step to improve heart health.”
A key outcome of the study is the development of a prediction tool—a nomogram—that combines screen time with other risk factors such as age, diet, and exercise habits. With an accuracy of over 90 percent, the tool could help identify individuals at high risk and support timely interventions.
“The nomogram provides healthcare professionals with a simple, visual way to predict hypertension risk,” said Dr Mingqi Zheng, one of the researchers. “This could significantly improve early detection and prevention efforts.”
Doctors in India warn that hypertension, a silent killer, often goes unnoticed until it causes complications like heart disease or stroke. They note that the number of young and middle-aged people being diagnosed with hypertension has risen over the past decade.
Speaking to South First, Dr Mohan V, renowned diabetologist and Chairman of Dr V Mohan’s Diabetes Clinic and Research Centre in Chennai, said, “We agree with the work of Liu and colleagues, which shows that screen time spent watching short videos was significantly associated with essential hypertension in young and middle-aged people.”
Dr Mohan agrees that screen time, especially watching videos at night, can be harmful in many ways.
He said, “Firstly, it is shown that light emitted from those devices can affect the brain. Secondly, this could influence the sleep pattern, as watching disturbing videos can affect sleep. The circadian rhythm can be affected, and this is one of the known causes of obesity, diabetes, hypertension, and heart disease.
“Finally, screen time adds to sedentary behaviour. It is said that sitting is the new smoking as far as non-communicable diseases are concerned, and in this sense, also, screen time at bedtime, watching short videos, is discouraged.”
Dr Mohan added that his centre for diabetes research had recently published a similar study on how screen time in adolescence led to obesity and other non-communicable diseases.
Referring to their study, Association of the perceived neighbourhood and home environments with sedentary behaviour among adolescents in 14 countries: the IPEN adolescent cross-sectional observational study, led by Dr Anjana RM and team, he said, “Our findings also confirmed that screen time in adolescence leads to obesity and other NCDs. The study was published in the International Journal of Behavioural Nutrition and Physical Activity.”
He noted that some countries, such as Australia, are already introducing legislation to regulate screen time and social media use among adolescents.
“This is a welcome move, as it can significantly improve the physical and mental health of adolescents,” he said.
Dr Sudhir Kumar, consultant neurologist at Apollo Hospital, told South First, “This association was dose-dependent, meaning those who spent more than four hours watching videos at bedtime had a higher risk—40 times higher—of hypertension compared to those who watched videos for three to four hours, whose risk was nine times higher.”
He explained possible reasons for the increased hypertension risk with prolonged video watching, including more sedentary time and sympathetic arousal, depending on the content of the videos.
Dr Kumar added that exposure to screens (via mobile phones, laptops, or TVs) at bedtime negatively impacts sleep quality and duration.
This includes increased sleep latency (time taken to fall asleep after turning off the lights), frequent awakenings, shorter sleep duration, and not feeling refreshed upon waking.
“Poor sleep, in turn, is linked to a higher risk of being overweight, obesity, type 2 diabetes, hypertension, cardiovascular diseases, and some types of cancer.
Excessive screen exposure close to bedtime can also increase stress and anxiety, depending on the content being watched. Watching a mobile screen in a dark room has even been reported to cause transient (short-duration) blindness,” he said.
🔴Screen time spent watching short videos at bedtime could be linked to a higher risk of hypertension (high BP)
➡️Findings of a recent research
1. The screen time spent watching short videos at bedtime was significantly associated with essential hypertension in young and… pic.twitter.com/bBk2WL7kSb— Dr Sudhir Kumar MD DM (@hyderabaddoctor) January 10, 2025
Meanwhile, Dr Deepak Krishnamurthy, a renowned interventional cardiologist at Kauvery Hospital, referred to the study and stated, “It is time for people to uninstall the apps and stop scrolling for videos at bedtime.”
Speaking to South First, Dr Deepak noted, “Clinically, we are seeing a significant rise in hypertension among the young over the past decade. Disturbed sleep and stress are key contributors, along with obesity, sleep apnoea, and lack of exercise.”
He added, “Hypertension is the leading risk factor for cardiovascular disease. It increases the risk of heart attacks, heart failure, kidney dysfunction, end-stage renal failure, dialysis, and brain strokes. In the long term, hypertension also raises the risk of dementia.”
Dr Sudhir Kumar, however, emphasised that the study only shows an association, adding, “More well-designed research is needed to confirm these observations.”
Dr Manoj Sharma of the SHUT Clinic at National Institute of Mental Health and Neurosciences (NIMHANS), who specialises in technology addiction, had earlier shared tips to help reduce bedtime screen time in an interview with South First.
(Edited by Dese Gowda)
