Not getting enough sleep can lead to heart health problems like high blood pressure or heart attacks. That's because lack of sleep can cause your body to release cortisol, a stress hormone that triggers your heart to work harder. Napping is not harmful, but it hampers the sleep quality that you need at night. Because of frequent naps, people are unable to get proper sleep when they need it i.e. during the night. It disturbs the clock that the body is used to. Why sleeping at night for 6-7 hours is better than power Naps.