Why does my teenager stay up so late and sleep until noon?

This isn't laziness — during puberty, the circadian rhythm shifts later by 1–3 hours (a biological change called 'sleep phase delay'), making teens naturally sleepy later and needing to sleep later. Teens need 8–10 hours of sleep but most get far less, creating a chronic sleep debt that affects mood, grades, and health. Encourage consistent sleep/wake times (even weekends), limit caffeine after noon, and keep phones out of the bedroom at night. Advocate for later school start times in your community. Consult your pediatrician if your teen's sleep problems are severe.