Sleep: why you're wired at midnight and wrecked at 7am

It's 11:30pm. You're not even slightly tired. You're watching one more video, replying to one more message. Then suddenly it's 1am. Your alarm goes at 7, and you feel like you've been hit by a bus. Someone asks you something at breakfast and all you can manage is a grunt.

You're not lazy, and you're not imagining it. Your body clock actually changes during your teens.

What's going on

Your body has an internal clock that tells you when to feel sleepy and when to feel awake. It uses a hormone called melatonin to make you tired at night. During puberty, that clock shifts later. Melatonin tends to arrive an hour or two later than when you were younger, so you genuinely don't feel sleepy until later.

The problem is that school doesn't move later. So a lot of teens are going to sleep late and getting up early, and ending up short on sleep most nights.

How much you need

Most teens need somewhere around 8 to 10 hours a night. Many get a lot less. And it adds up. Being short on sleep for days on end is like carrying a sleep debt around, and your body keeps count.

What a sleep debt does

When you're short on sleep, pretty much everything gets harder:

• Mood. You're more irritable, and small things feel bigger.
• Focus and memory. Learning is harder, and your brain holds onto less.
• Anxiety and low mood. Poor sleep and feeling down or anxious often go together.
• Energy. Sport, practice, even just getting through the day.
• Arguments. Tired people fight more. That includes you and your parents.

What actually helps

You can't completely override your body clock, but you can nudge it. Some things that make a real difference:

• Morning light. Get outside or near a window soon after you wake up. Bright light in the morning helps shift your clock earlier.
• Dim things down at night. An hour before bed, turn the lights down and the screen brightness right down, or use night mode.
• Phone out of reach. If your phone is next to your bed, it's very hard not to pick it up. Charging it across the room, or outside your room, helps a lot.
• Keep weekends close. Sleeping in until 1pm on Saturday makes Monday morning brutal. A bit of a sleep-in is fine, but try to keep it within a couple of hours of your usual time.
• Watch the caffeine. Energy drinks and coffee in the afternoon can keep you wired well into the night.
• Wind down. A shower, music, reading, anything that isn't a screen and tells your body the day is done.

If you still can't sleep

If you're lying awake for ages, get up, do something calm in dim light for a bit, then try again. And if poor sleep has been going on for weeks, or it's tied up with worrying, feeling down, or something else going on, talk to a parent or your GP. Sleep problems are really common, and there's help.