How Much Sleep Do I Need?

Somewhere you read that eight hours is the magic number. You get six and a half on a good night. You’ve heard people say they thrive on five, and you’ve watched a coworker sleep nine on weekends. You’d like a straight answer, and you’d like it without a lecture.

Hours aren’t the whole story

The CDC¹ describes quality sleep as uninterrupted and refreshing sleep. So eight hours that you spend waking six times, or with undiagnosed sleep apnea, may not count the way it should. See waking at 3 a.m. and waking up to pee.

Why it matters

The National Heart³, Lung, and Blood Institute (NHLBI) says about 1 in 3 adults in the US report not getting enough rest or sleep every day. It says sleep deficiency is linked to many chronic health problems, including heart disease, kidney disease, high blood pressure, diabetes, stroke, obesity and depression, and to a higher chance of injury. It lists drowsy driving as particularly dangerous.

What the CDC lists for better sleep

• A steady bedtime and wake time
• A bedroom that’s quiet, relaxing and cool
• No screens for at least 30 minutes before bed
• No heavy meals or alcohol before bed
• Less caffeine in the afternoon and evening
• Regular exercise and good nutrition

The NHS² adds a relaxing sleeping area that isn’t too bright, noisy or warm, and avoiding smoking, excess alcohol and screens before bed. See trouble falling asleep and melatonin.

If you’re sleeping enough and still tired

The NHS² lists causes of ongoing tiredness beyond sleep, including iron deficiency anaemia, diabetes and thyroid disorders, and says a GP may order blood tests to rule them out. It says to see a GP if you’ve been tired for a few weeks and you’re not sure why. See why am I always so tired.

The play

Try this: a two-week sleep log

For two weeks, write down the time you got into bed, roughly when you fell asleep, how many times you woke, when you got up and how you felt at 10 a.m.

Count the hours. Compare with the CDC’s¹ range for your age.

Pick one change from the list above and keep it for the whole two weeks.

When to get checked

The NHS² says to see a GP if you’ve been tired for a few weeks and aren’t sure why. The CDC’s¹ definition of quality sleep, uninterrupted and refreshing, is a useful test: if yours is neither, that’s information.

Book an appointment if any of these fit:

• You’re short of the recommended hours for weeks and can’t fix it
• You sleep the recommended hours and still wake exhausted
• You snore, gasp or have been told you pause for breath
• You fall asleep during the day, or while driving
• Your sleep changed around menopause and nothing helps
• You have heavy periods, thirst or other symptoms along with tiredness

Seven hours is the floor for most adults, and a reasonable one. If you’re not reaching it, the sleep log tells you where the hours are going.