We often associate bright, well-lit spaces with productivity and comfort. But new research suggests your evening lighting habits might be silently harming your heart.. A study published in the JAMA Network on October 23, 2025, found that exposure to bright light at night may significantly increase the risk of heart disease. The researchers discovered that keeping your home brightly illuminated after sunset can disrupt your circadian rhythm — the body’s internal clock that regulates sleep, hormone balance, and vital physiological processes.. DISCLAIMER: This article is based on information from the public domain and/or the experts we spoke to. Always consult your health practitioner before starting any routine.. “When the body’s internal clock is disrupted, heart health is also affected,” the study noted. Bright light at night, they explained, “throws the body’s internal clock off rhythm,” triggering a chain of physiological reactions, such as increased blood pressure, inflammation, and a faster heart rate. Over time, these responses add up, paving the way to cardiovascular problems.. The study’s findings were striking: people exposed to the brightest night light faced a 32% higher risk of coronary artery disease, a 56% higher risk of heart attack, and a 30% higher risk of stroke. Even more concerning, these risks remained independent of lifestyle factors such as diet, exercise, genetics, and overall sleep duration.. While shift workers are especially vulnerable because their schedules expose them to light at biologically inappropriate times, researchers also warn that the same risks may apply to anyone who scrolls through their phone in bed or sleeps with the lights on. The takeaway, they said, is simple: dim your indoor lights after sunset, use heavy curtains, and avoid screens before bed to protect your cardiovascular health.. But what happens inside the body when the circadian rhythm is disrupted that makes the heart more vulnerable?. Dr Raj Kumar, senior consultant, Non-invasive Cardiology at PSRI Hospital, tells indianexpress.com, “When our body is exposed to bright light at night, it interferes with the natural circadian rhythm — the internal clock that regulates sleep, hormones, and body temperature. Normally, melatonin levels rise after sunset, signalling the body to rest. But artificial light suppresses melatonin production, causing stress hormones like cortisol to remain high.”. Story continues below this ad. This increases heart rate, blood pressure, and inflammation. Over time, this constant imbalance can strain the cardiovascular system, disturb glucose metabolism, and make blood vessels less flexible, all of which heighten the risk of heart attacks and other cardiac problems.. ALSO READ | Cardiologist lists everyday habits that are ‘actually affecting your heart — and nobody’s talking about it’. How can people realistically reduce their night-time light exposure without compromising comfort or routine
