Can naps affect my nighttime sleep cycles?

Yes, naps can affect nighttime sleep, especially if they are long or taken late in the day. A nap reduces sleep pressure, which is the natural drive that builds the longer you remain awake. This can make it harder to fall asleep at bedtime or reduce the amount of deep sleep early in the night. Short naps of around 10 to 30 minutes earlier in the afternoon are less likely to cause problems for most people. Longer naps may include deeper sleep and can leave you groggy, although they may be useful for shift workers or people recovering from sleep loss. If you have insomnia, limiting naps may help. Pay attention to whether napping changes your bedtime or nighttime waking.