Sleep is essential and yet many people get insufficient sleep or have poor sleep quality. A recent review gives the following stats:

Population studies show that sleep deprivation and disorders affect many more people worldwide than had been previously thought. A recent study found 20% of 25–45 year-olds slept “90 minutes less than they needed to be in good shape”. Insomnia is the most common specific sleep disorder, with ‘some insomnia problems over the past year’ reported by approximately 30% of adults and chronic insomnia by approximately 10%. Prevalence of obstructive sleep apnoea, characterized by respiratory difficulties during sleep, is also very high with estimates of 9–21% in women and 24–31% in men.

The CDC considers poor sleep a public health problem. As a practicing physician these statistics also match my experience. Poor sleep is comorbid with many neurological conditions I treat, such as migraine. What I find interesting is how many patients I see who are having frequent migraines, they have fatigue, have difficulty with weight control, and are having difficulty with concentration and short-term memory. Further, when asked they report having terrible sleep, and yet they did not volunteer this information or make any connection to their other symptoms.

What this tells me is that people under-appreciate the importance of sleep and the negative consequences of chronic poor sleep. In fact, many patients are initially dismissive of the idea that poor sleep could be a major explanation for their symptoms. They are used to having poor sleep and that is now their normal.

The ultimate test, of course, is what happens when you fix their sleep. Some patients have a clear sleep disorder, like sleep apnea (the airway closes when they are asleep causing obstruction leading to eventual loud snoring and gasping which wakes the patient but not fully, so they often don’t remember the event). Sleep apnea can be treated, for example with a breathing mask providing positive airway pressure (CPAP). Typically the patient’s other symptoms are dramatically improved once their sleep is improved.

For these reasons there is increased interest in the effects of sleep deprivation. One ongoing study looks at the performance of people on online tasks testing cognitive function. They are also comparing functional MRI scan when performing cognitive tasks in the rested and sleep-deprived state. This will be the largest study to date. But there are already studies looking at cognitive function and overnight work shifts or poor sleep and they consistently find (no surprise) that lack of sleep impairs performance.

Sleep Hygiene

What to do if you suspect you are suffering from poor or inadequate sleep? In many cases it may be appropriate to consult a physician. Many sleep disorders can only be diagnosed with a sleep study (polysomnography).

Everyone, however, should be aware of what constitutes good sleep hygiene, and many poor sleep problems can be fixed by making some basic lifestyle changes. Here are some basic rules:

First, try to have a regular sleep cycle. This is difficult for shift workers, which is why shift work sleep disorder is its own thing. Many people also have young children or other responsibilities that make it impossible to have an absolute priority on sleep. But prioritize sleep as much as you can.

Most people should avoid napping during the day in order to make up for lack of sleep at night. If you have general good sleep, there is nothing wrong with a brief siesta. However, it can be counterproductive to nap in order to make up for poor sleep at night. The problem is this breaks up your sleep. It is better to get all your sleep at once, so that you have time to get into the deeper stages of sleep. You are better off staying awake during the day so that you are more sleepy at night.

For the same reason, if you have trouble falling asleep, don’t stay in bed tossing and turning. Get out of bed, read a book, do something relaxing. When you feel sleepy, get back into bed. The reason for this is that while you are tossing and turning you are getting brief mini-naps, that also serve to break up your sleep and frustrate establishing a full sleep cycle.

Light levels are also important. We evolved without electricity so our brains are used to sunlight during the day and low light during the night. In fact, low light levels trigger the brain to release melatonin which induces sleep. In our modern world we have consistent light levels all day and night, then hop into bed. So, get some sunlight during the day if you can. In the evening, start to turn off or turn down lights. Get your brain ready for sleep.

Further, avoid electronic devices in bed or prior to sleep. While this is a relatively recent phenomenon, there is already evidence that screen time in the evening is bad for sleep.

By the way, the evidence for melatonin supplements in primary and secondary sleep disorders is mixed and unconvincing. There is some preliminary evidence for possible benefit, but better trials are needed.

Caffeine is probably one of the worst enemies of sleep. Caffeine directly disrupts the brain’s sleep cycle, and also frustrates sleep onset. Further, daily caffeine use rapidly develops dependence. Even caffeine consumed earlier in the day (as late as noon) can be disruptive to sleep onset. Anyone with disordered sleep should try to completely remove caffeine for at least 6 weeks to see what effect it has.

Other recommendations include to avoid eating or drinking right before bedtime. Eating can cause reflux when lying down. You should also try to empty your bladder and time your fluid intake so that you can get through the night without waking up to pee. Of course, there are conditions that make this impossible, but otherwise that’s the goal.

Make sure your pillow and mattress have enough support and are comfortable for you. Back pain from a saggy mattress is an easy (if expensive) problem to fix. You may also be able to get away with a mattress top for extra support or comfort. Essentially, do what you need to do in order to get through the night comfortably. If you do wake up during the night, try to figure out why.

There is also evidence that exercise during the day improves sleep quality.

This is all generic advice for good sleep hygiene, but of course individuals may have medical issues or specific problems that need to be addressed. There is no reason not to have good sleep hygiene, however, and it is always a good start when addressing poor sleep. When in doubt, however, consult your physician.

The start, however, is to think about your sleep. Chronically poor sleep is often the cause, or at least is a significant exacerbating factor, in many common “symptoms of life” like fatigue, muscle pain, headaches, and poor concentration. Don’t ignore poor sleep or fail to address it as a real problem.