Is 6 hours of sleep enough?

Is 6 hours of sleep enough?

For most adults, no. The NHS says adults need 7 to 9 hours on average. Two US sleep science groups advise 7 or more hours a night, on a regular basis.

The NHS page on tiredness gives a wider aim of 6 to 9 hours. So 6 sits on the very bottom edge.

Under 7 hours most nights is linked to weight gain, diabetes, high blood pressure, heart disease, stroke and depression. Linked means seen together, not proven to cause.

Is 7 hours enough? It’s inside the NHS range. But if you’re constantly tired by day, you probably need more.

Your first move: count back 7 hours from your alarm. That’s your latest bedtime.

Why 6 hours of sleep can feel fine

In a US lab study, 48 healthy adults aged 21 to 38 took part. Some spent 4, 6 or 8 hours in bed a night for 14 days. Others went 3 nights with no sleep, for comparison.

On 4 or 6 hours, their focus tests got steadily worse over the two weeks. By the end, 6 hours or less had dulled focus as much as up to 2 nights with no sleep at all.

Yet how sleepy they felt barely changed after the first few days. The researchers say people were largely unaware of how far they had slipped.

That’s the trap. Feeling used to 6 hours isn’t the same as doing fine on it.

So don’t judge by feel alone. Track your nights and your days for two weeks in a sleep diary.

Using a watch? Check how accurate sleep trackers are first.

4, 5, 6 and 7 hours of sleep compared

A US study of 6,845 drivers in crashes asked how long each had slept in the 24 hours before. The less sleep, the higher the odds they caused the crash.

Short nights were also linked to colds. In one study, 164 healthy adults were given a cold virus on purpose. Their sleep was measured by a wrist device over the week before.

Those sleeping under 6 hours had about 4 times the odds of catching the cold of those sleeping over 7. Those on just over 6 up to 7 hours were at no greater risk.

Both studies show a link, not proof. Your move: after 6 hours or less, don’t drive if you feel sleepy.

What about 3 or 4 hours of sleep?

This is where the driving risk jumps. Under 4 hours came with 15.1 times the odds of causing a crash.

In the lab study, 4 hours a night for two weeks hurt focus more than 6 did.

Lost sleep over a few nights? See what weekend catch-up sleep can and can’t do.

I only sleep 4 or 5 hours a night. Is it insomnia?

It may be. The NHS calls it insomnia when sleep problems happen regularly. You find it hard to get to sleep, wake several times, lie awake, or wake early and can’t get back to sleep.

You may still feel tired after waking, or tired, irritable and unable to focus in the day.

Under 3 months is short-term insomnia. 3 months or longer is long-term. It usually gets better when you change your sleep habits.

Coffee in the afternoon? Find your caffeine cut-off for sleep.

Habits not helping? Your GP may offer cognitive behavioural therapy (CBT). It’s a talking therapy that changes the thoughts and habits that keep you awake.

See CBT for insomnia.

When to speak to a GP

Book an appointment if:

• Changing your sleep habits hasn’t helped, or you’ve had trouble sleeping for months.
• Short sleep makes daily life hard to cope with.
• You’ve felt tired for a few weeks and don’t know why, tiredness affects your daily life, or you’re tired and also have weight loss or mood changes.
• Your breathing stops and starts in your sleep, or you gasp, snort or choke. These are main signs of sleep apnoea, when your breathing keeps stopping and starting as you sleep. Another is always feeling very tired during the day. Bring the person who saw it, if you can.

Many medicines can cause insomnia. Never stop or change a prescribed medicine without your prescriber.

Sleeping 7 hours or more and still tired? See why you might be always tired, or read how much sleep you need by age.