An inconsistent bedtime schedule may be doing more harm than simply making you feel tired the next day. Doctors warn that going to sleep at very different times each night can disrupt the body’s internal clock, known as the circadian rhythm, and may increase the risk of serious cardiovascular problems such as heart attacks and strokes—especially among adults who regularly get less than eight hours of sleep.

When your sleep timing constantly changes, your body struggles to maintain normal patterns. This disruption can place extra stress on the cardiovascular system, affect hormone balance, and interfere with the natural nighttime drop in blood pressure. Over time, these changes may contribute to increased inflammation and strain on the arteries. The risks become even greater when irregular bedtimes are combined with short sleep duration.

Other nighttime habits can also damage sleep quality. Drinking alcohol before bed may make you feel sleepy at first, but it can interrupt deep sleep and prevent your body from fully recovering. Using phones, tablets, or other bright screens in a dark room can suppress melatonin production, keeping the brain alert when it should be preparing for rest.

Spending too much time in bed while awake may also be linked to poorer sleep quality and cognitive issues in older adults. Experts recommend maintaining a consistent bedtime, creating a relaxing nighttime routine, limiting screen exposure before sleep, and aiming for enough quality rest each night. Small changes to your sleep habits can have a meaningful impact on long-term health.