Most adults need about 7 to 9 hours of sleep a night, and people over 65 about 7 to 8. Needs vary from person to person, so how rested you feel during the day matters as much as the number of hours.

Yes. Caffeine can stay in your system for many hours, so a mid-afternoon coffee can still affect how easily you fall asleep and how deeply you sleep. Many people sleep better when their last caffeine is before lunch or early afternoon.

It can make you feel drowsy at first, but alcohol tends to disrupt sleep later in the night, making it lighter and more broken. Keeping evening drinks small, or having alcohol-free nights, often improves sleep quality.

It can. Large or late meals, spicy or rich food close to bed, and going to bed hungry can all make it harder to settle. Short or poor sleep can also increase appetite and cravings the next day, which is why sleep matters for nutrition goals.

See your GP if poor sleep has lasted three months or more, if you snore loudly or stop breathing or gasp during sleep, if you feel very sleepy during the day, or if sleep problems are affecting your mood, work or driving.