The serious consequences of sleep deprivation perennially capture society’s attention. And, as kids head back to school, sleep and a lack of it are of particular concern.

Compared to historical norms, how have our contemporary expectations of sleep changed? What are the effects of inadequate sleep? What can be done to optimize the experience of sleep, especially in the context of insomnia?

I am a clinician and sleep researcher who treats people with sleep problems. I think there is little reason to suspect that our collective sleep needs have dramatically changed in the recent past, rooted as they are in immutable physiological processes. We should, however, be paying attention to our sleep needs, and that isn’t as hard as it sounds.

What is sleep anyway?

From a clinical perspective, sleep is defined as a reversible behavioral state of unresponsiveness and perceptual disengagement from the environment. It is dependent on the balance between sleep drive – the desire for sleep that builds during wakefulness and is linked to the accumulation and clearance of chemicals within the brain like adenosine – and the circadian alerting signal. The circadian rhythm coordinates processes of the body to the environmental patterns of light and darkness. Adequate sleep is and always has been restorative to the body. Giving sleep respect, and preserving it to the benefit of health, has not been so permanent.

Researchers have learned more about sleep in the past 100 years than in all the preceding millennia combined.

The advent of, and inexpensive access to, artificial light no doubt marked a significant shift in this history. Scientific understanding of sleep continues to evolve and remains incomplete.

Nevertheless, it does seem that people are sleeping less now than they have in the past several decades. Recent self-reported national polling among American adults consistently suggests that Americans are not getting adequate sleep. This begs the question: How much sleep do people really need?

Sleep needs change over the lifespan

Sleep needs change over one’s lifetime. Toddlers may require 11 to 14 hours of sleep to feel rested and typically take naps.

Through adolescence, the need for sleep diminishes until it approaches the adult average. A typical adult requires from seven to nine hours of sleep nightly to avoid the effects of sleep deprivation. Adults older than 65 years may require just seven to eight hours of sleep.

Surveys suggest that 35 to 40 percent of the adult population sleeps less than seven to eight hours on weekdays. This self-reported sleep data may overestimate the objectively measured sleep obtained by up to one hour, due to time spent falling or getting back to sleep. We are in trouble.

If someone eats too many calories, or too few, the effects on the body become apparent. Unfortunately, there is no “sleep scale” to step onto to gauge the physical tolls of sleep deprivation. Sleep deprivation, either from not allotting enough time to get sufficient sleep or due to sleep disorders like insomnia, may have important consequences.

Bad for the brain?

Beyond sleepiness, sleep deprivation wreaks havoc on the brain, affecting mood and worsening depression, exacerbating pain and undermining executive functions that affect judgment, planning, organization, concentration, memory and performance. Hormones influencing weight and growth become imbalanced. Immune dysfunction, leading to an increased susceptibility to illness, and a pro-inflammatory state develop.

Sleep deprivation can become deadly, too. The increased risk of fatal traffic accidents associated with lost sleep parallels that linked to alcohol consumption. Those who sleep fewer than five hours per night have two to three times the risk of a heart attack. Chronic sleep loss may slowly undermine the central pillars of health.

Ditch the digital devices, keep a routine

How can we avoid the perils of inadequate sleep?

First, prioritize sleep and ensure that you are obtaining sufficient hours to feel rested. Ensure an easy transition to sleep by maintaining an hour to unwind with relaxing activities before going to bed.

Reserve the bedroom as a space for sleep: leave electronic devices elsewhere.

Keep a regular sleep-wake schedule, especially fixing the wake time, including on weekends.

Get 15 to 30 minutes of sunlight upon awakening, or at sunrise.

Always go to bed feeling sleepy, even if that means delaying bedtime a little.

As needed, consider reducing the time in bed if more than 30 minutes is consistently spent awake.

Be physically active.

Moderate the use of alcohol and caffeine.

When sleep problems persist, get help.

If these do not work, consider evaluation by a board-certified sleep physician. Chronic insomnia may respond well to cognitive behavioral therapy for insomnia. This treatment is increasingly accessible via trained therapists, workshops, online courses and books.

Symptoms such as frequent or early awakenings, excessive daytime sleepiness, snoring, witnessed pauses in breathing, frequent peeing at night, night sweats, teeth grinding, and morning headaches may suggest the presence of sleep apnea. A comprehensive evaluation and appropriate testing may lead to an effective treatment.

Sleep should come naturally. It should never become an additional source of stress. Simple adjustments can yield benefits quickly.

Fortunately, the first step to better sleep is recognizing its importance – an objective that has hopefully been achieved. Now, consider making a few changes and, as necessary, access further resources to yield the long-term benefits to health and well-being that only sleep may provide.

Brandon Peters-Mathews does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.