Delayed Sleep Phase Syndrome (DSPS) is a sleep disorder where a person struggles to fall asleep until very late at night, sometimes as late as 4am. This often makes waking early difficult, causing grogginess in the morning and higher energy levels later in the day. DSPS is thought to be linked to disruptions in the body clock and melatonin production. Lifestyle habits can also contribute, especially in young people who naturally feel less sleepy at night and stay up later, shifting their sleep cycle over time.