Staying up late on a regular basis may increase the risk of heart attack and stroke, according to growing medical evidence linking sleep habits with cardiovascular health. Doctors and researchers caution that consistently going to bed late can disrupt the body’s internal clock, leading to long-term stress on the heart and blood vessels even in otherwise healthy individuals.

At the core of this risk is disruption of the circadian rhythm, the body’s natural 24-hour cycle that regulates sleep, blood pressure, heart rate, and hormone release. When people stay awake late into the night, especially past midnight, this rhythm becomes misaligned. Studies suggest such disruption can lead to higher nighttime blood pressure and reduced recovery time for the cardiovascular system.

Late sleeping is also associated with increased levels of stress hormones, including cortisol, which can remain elevated when the body should normally be resting. Over time, persistently high cortisol levels contribute to inflammation, insulin resistance, and abnormal cholesterol levels, all of which are known risk factors for heart attacks and strokes.

Another contributing factor is sleep quality and duration. People who stay up late often get shorter or fragmented sleep, particularly on workdays, leading to chronic sleep deprivation. Poor sleep has been linked to irregular heart rhythms, higher blood sugar levels, and weight gain, compounding cardiovascular risk. Even those who sleep for adequate hours during the day may not receive the same restorative benefits as night-time sleep.

Lifestyle patterns common among late sleepers can further worsen the problem. Late-night eating, reduced physical activity, increased screen exposure, and higher consumption of caffeine or alcohol are behaviours frequently associated with staying up late and are independently linked to heart disease.

Health experts advise maintaining a consistent sleep schedule, ideally sleeping and waking at the same time daily, to reduce cardiovascular strain. Prioritising 7–8 hours of quality night-time sleep, limiting screen use before bedtime, and adopting heart-healthy habits can significantly lower the long-term risk of heart attack and stroke linked to poor sleep patterns.