Sound sleep: Why you need it, how to get it

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Are you feeling well rested? That’s rarely down to chance - we can influence it. And we should, because restful sleep is the foundation for concentration, mood and health. We asked sleep specialists what they recommend

Battina Lüke, DPA

Monday, 20 April 2026, 12:00

You may be one of the many people who often slog through the day tired, unconcentrated and irritable. The remedy? A restful night's sleep. It not only lets you start the day more alert and fit to face what it brings, but also has long-term health benefits.

Restful sleep isn't a luxury, but a fundamental biological need that plays a crucial role in both physical and mental health, health experts say. Your heart, immune system and brain all benefit greatly from sound sleep.

Large population studies have shown that people who sleep well live longer - men by nearly five years on average, and women by more than two.

Sleep is anything but wasted time. During deep sleep, also known as slow-wave sleep (SWS), growth hormone - a protein made by the pituitary gland - is secreted into the bloodstream, sleep medicine specialist Dr Michael Feld was recently quoted as saying in a German health publication. Among other things, it's important for skin, bones and wound healing.

Your immune system is also hard at work while you sleep, helping the body to combat inflammation and strengthening immune reactions - for example after a vaccination.

Sleep is particularly important for your brain. It's when memories are consolidated, irrelevant details removed and new neural connections formed.

What's more, the glymphatic system - a brain-wide fluid pathway - is active during SWS, which helps clean the brain by removing potentially harmful metabolic waste products. Long-term sleep deficiency may be a risk factor for Alzheimer's disease.

How much sleep is sufficient?

The amount of sleep a person needs depends on the individual. For most adults, seven to nine hours per night is regarded as optimal, says Birgit Högl, professor of neurology at the Medical University of Innsbruck and director of its sleep laboratory.

If you regularly sleep considerably less, you risk undermining your concentration, mood and ability to make decisions. Making up for a "sleep debt" - say, by sleeping longer at the weekend - or "banking" sleep with extended sleep before an anticipated period of little sleep is only effective to a degree.

When is sleep insufficiency seen as a medical disorder?

Although definitions differ, experts generally characterise trouble falling or staying asleep at least three nights a week for at least one month, resulting in fatigue the following day, as persistent insomnia disorder. If the symptoms last for three months or longer, the disorder is considered to be chronic.

Left untreated, insomnia can increase the risk of diabetes, cardiovascular diseases, obesity, depression and Parkinson's disease.

If you have trouble sleeping over a period of months, snore loudly or constantly feel tired during the day, you should see a doctor. Medications are usually prescribed only when other treatment methods fail to help, because sleeping pills have side effects and can become addictive.

There are many practical tips on getting a good night's sleep. Among them are drinking no post-afternoon caffeine, getting daytime exercise but refraining from vigorous physical activity in the evening, not eating heavy meals in the evening, and avoiding alcohol and cigarettes too, which disturb SWS.

Other tips include sticking to a regular sleep schedule, having a consistent bedtime ritual, keeping your bedroom cool (16-18 degrees Celsius) and making sure your mattress, pillow and blanket are right for you.

Your bedroom should be dark and as quiet as possible when you sleep, and you shouldn't have a smartphone, computer or television set in the bedroom, a place that should be reserved for sleep and sex. Speaking of sex, it - or less intimate, relaxing physical contact - can help some people fall asleep.

And if you lie awake for a long time, it's best to get up, do something monotonous, and go back to bed when you feel sleepy.