Sleeping with the lights on? How it may affect your health, from heart disease to diabetes

Exposure to light while sleeping, from bedside lamps, mobile devices, televisions, or streetlights, may seem harmless, but research suggests it could affect sleep quality and overall health. Experts warn that disrupting the body’s natural sleep-wake cycle could have long-term consequences.

Also Read: What is fatty liver disease: Causes, symptoms, and foods and natural drinks that can help, according to Harvard-trained gastroenterologist

Impact on sleep and the body’s internal clock

Sleeping with lights on can disrupt the body’s circadian rhythm, the internal clock that regulates energy, hormone release, and vital bodily functions. According to the National Heart, Lung, and Blood Institute (NHLBI), these disruptions may contribute to poor sleep quality and increase the risk of certain health problems, including heart disease.

Heart health risks linked to nighttime light exposure

Preliminary studies indicate that even dim light during sleep may affect heart function. Exposure to artificial light while sleeping has been associated with increased heart rate and higher blood pressure, potentially raising the risk of heart disease, as per the study.

Nighttime light and obesity

Some research indicates that sleeping with televisions or bright lights on may increase the likelihood of obesity. A study reported by the National Library of Medicine, Biotech Information (NIH) found that women who slept with a light or TV on were more prone to weight gain over time. Exposure to blue light at night may be particularly problematic, though using a small nightlight appears to carry minimal risk.

Potential Link to Diabetes

Sleeping with lights on may also affect insulin resistance, a precursor to diabetes. A small study highlighted by the National Center for Biotechnology Information found that light exposure during sleep could impair the body’s ability to process sugar effectively. While further research is needed, prolonged exposure to artificial light at night may be linked to an increased risk of diabetes.

When nighttime lights may be necessary

While sleeping in darkness is generally recommended, experts acknowledge some exceptions. Nightlights can help children who are afraid of the dark and older adults who need to navigate during the night safely. In such cases, experts advise using dim, warm-colored lighting to reduce potential harm.


Disclaimer: This article is for informational purposes only and is not a substitute for professional medical advice. Always seek the advice of your doctor with any questions about a medical condition.