Sleep affects everything from your heart health to your weight and mental clarity. Here's what the science actually says.
General information, not medical advice — see terms of use.
The American Academy of Sleep Medicine recommends adults get at least 7 hours of sleep per night. Most adults need 7–9 hours.
What happens with insufficient sleep:
- Less than 6 hours: Significantly increased risk of obesity, diabetes, cardiovascular disease, stroke, depression, and early death
- A single night of 6 hours impairs reaction time and decision-making comparable to being legally drunk
- Sleep loss increases appetite and cravings for high-calorie foods by disrupting hunger hormones
- People sleeping less than 6 hours are 4x more likely to catch a cold when exposed to a virus
Signs you're not getting enough sleep:
- Needing an alarm clock to wake up
- Afternoon fatigue requiring caffeine or naps
- Falling asleep within 5 minutes of lying down
Sleep hygiene tips that actually work:
- Consistent sleep and wake times (even weekends)
- Keep bedroom cool (65–68°F / 18–20°C)
- No screens 1 hour before bed
- Avoid caffeine after 2pm
- Limit alcohol (disrupts sleep architecture despite helping you fall asleep faster)
Follow-up questions
Is it bad to catch up on sleep on weekends?
Yes. Social jet lag — sleeping significantly more on weekends — is associated with cardiovascular disease and metabolic problems. Consistent sleep schedules are far healthier than variable patterns.
What causes insomnia and how is it treated?
Common causes include stress, anxiety, depression, irregular schedules, caffeine, and alcohol. Cognitive Behavioral Therapy for Insomnia (CBT-I) is the most effective treatment — more effective than sleep medications with lasting results. CBT-I has a 70–80% success rate.
How does sleep affect weight?
Sleep deprivation raises ghrelin (hunger hormone) and lowers leptin (fullness hormone), leading to increased appetite and cravings for high-calorie foods. Studies consistently show that people who sleep less weigh more. Getting adequate sleep is an underrated component of any weight loss effort.
This page is general information, not medical advice, and it may not reflect the latest rules where you live. For your own situation, talk to a qualified clinician. Spotted an error? Email per@upperia.se and we will fix it.