Insomnia – when is it a disease and what are the health consequences?

Why is sleep so important for the body?

Sleep occupies one-third of our lives. Like all animals, humans need sleep to survive. During sleep, the brain regenerates. Memory traces are consolidated, and memories are organized – important ones are retained, while unnecessary ones are discarded so they do not take up space. Sleep also improves brain neuroplasticity, which is its adaptive capacity. All of this allows us to function optimally during the day. Neglecting sleep is unwise. I often tell students that it’s not worth staying up all night before an important test or exam. Even if it seems that we haven’t memorized the material well yet, we shouldn’t torture ourselves; we should just go to sleep. A study on students preparing for an exam found that those who reviewed their notes and then slept and rested had a much better grasp of the material in the morning and performed better on the exam. Those who studied all night, however, did not get enough rest and had worse results.

How long can someone go without sleep? 

This is very difficult to study and, above all, unethical. Currently, studies in which someone would be deprived of sleep are prohibited. However, from past experiments, we know that it is very difficult to induce a state in which a person truly does not sleep. People subjected to prolonged sleep deprivation fall asleep even under poor conditions, such as standing up with their eyes open. A Russian physician conducted a cruel study on puppies, preventing them from sleeping. It turned out that lack of sleep led to death faster than deprivation of food or water. 

Does everyone need the same amount of sleep, or does it change with age?

Adults need six to eight hours of sleep. Children need more, and seniors need less. With age, not only does the need for sleep decrease, but its quality also worsens – this is completely natural. 

Is it true that a “lost” night can be made up for? 

Humans are evolutionarily well-adapted to single episodes of sleep deprivation. For most of human history, humans lived a nomadic lifestyle – there were situations when it was necessary to stay alert, to fight, or to flee at night. Therefore, one sleepless night is not a major problem for the body. This is especially true because the next night, the body will be more in need of sleep, and we will have a greater amount of deep (slow-wave) sleep. Our sleep will be better, deeper, and more restorative. This mechanism, unfortunately, does not work when it comes to chronic deprivation – for example, during the week we sleep too little (four to five hours), and on the weekend we try to compensate with twelve hours. A study followed young men living a lifestyle typical of young professionals. They worked a lot during the day, they went out with friends in the evenings, they went to bed late, and woke up very early. On the weekend, they tried to make up for it. It turned out that their blood glucose levels worsened, their immune function declined, their memory performance was impaired, and their cardiovascular function also deteriorated. This shows that certain deficits caused by lack of sleep cannot be fully compensated. 

You mentioned slow-wave sleep – is this the most important type of sleep?

Every phase of sleep is important and necessary, but we do need slow-wave (deep) sleep the most. We know that sleep consists of cycles that repeat every one and a half to two hours. After we fall asleep, sleep deepens progressively and then becomes shallower, before the next cycle begins. During slow-wave sleep, that is, the deepest sleep, our brain works slowly and very synchronously, meaning all cells operate in the same rhythm. This is highly restorative. We also have REM sleep (rapid eye movement) – it is the phase in which the brain works similarly to the waking state, quite intensively. This phase of sleep is associated with emotional regulation.

Is it in REM sleep that we experience dreams?

We dream throughout the night. Dreams that appear during REM sleep are simply better remembered and are also more complex. We do not remember what we dream about during slow-wave sleep, and these are usually simple images. 

Recently, naps have become fashionable, including power naps – that is, a nap after drinking a cup of coffee. Is this a good idea?

It depends. People with sleep problems should definitely avoid naps. The longer they are and the later in the day they occur, the more they can disrupt nighttime sleep. Even people who do not have sleep problems can develop them if they sleep long at night and also try to nap during the day. To minimize the impact of a nap on nighttime sleep, the nap must be short. A power nap is exactly that – 15–20 minutes. We drink coffee before lying down to help wake us up. From the perspective of the cardiovascular system, any nap provides some recovery. However, they can be problematic if we take into account nighttime sleep quality.

Let’s move on to the sleep problems you mentioned – what do patients most often report? 

Statistically, after infections and gastrointestinal problems, insomnia is the third issue that prompts patients to visit their primary care physician. It is a very common problem. In our Sleep Disorders Clinic, insomnia is likewise the most common condition we see. However, we also treat patients with parasomnias, e.g., somnambulism (sleepwalking), or with narcolepsy (excessive daytime sleepiness). 

Is insomnia a disease, or is it a symptom accompanying other conditions? 

Insomnia is a separate disease because it requires separate treatment. However, it very often accompanies other conditions. It is therefore a warning signal that something worrying is happening. Sometimes, when we cure a coexisting disease, we also eliminate sleep problems. However, the disease may be cured, but insomnia remains. Therefore, it always needs to be addressed separately. 

What criteria must be met to diagnose insomnia? 

We speak of insomnia when a patient has sleep problems – difficulty falling asleep, night awakenings, or short sleep – leading to impaired daytime functioning. Insomnia involves heightened arousal throughout the day and night. This situation must occur at least three days per week and last for at least one month. These are the criteria for chronic insomnia. We may also deal with occasional insomnia – a few nights of poor sleep – or short-term insomnia, lasting up to four weeks. However, these last two types usually do not require treatment. 

What diseases may be accompanied by insomnia? 

Most often, insomnia accompanies anxiety disorders, neurotic disorders, and depressive states. Sleep problems also occur in psychoses or bipolar affective disorder. They often accompany somatic diseases, especially those involving pain. They also occur in Parkinson’s disease and other neurodegenerative disorders. Insomnia may also be caused by breathing difficulties or cardiovascular problems. Very often, stress is the trigger. Difficulty falling asleep and night awakenings are linked to stress, neurotic disorders, and somatic diseases, whereas waking between 3:00 and 4:00 a.m., causing insufficient sleep, is usually associated with depressive states. 

Many of these complaints affect older people. Is insomnia more often a problem for seniors? 

Indeed, the older the population, the greater the prevalence of insomnia. This results from several factors. First, sleep quality worsens with age, making it easier to disturb it. In addition, the risk of various mental and somatic diseases increases. Life patterns also change – after you retire, your regular day-night rhythm is disrupted, and activity decreases. All of this negatively affects sleep quality.

Can sleep problems be genetically determined? 

Yes, there are studies showing that insomnia is inherited, particularly from the mother.

What should we do when we sleep poorly? Are there any methods we can use to help ourselves? 

I often compare insomnia to diabetes because they have many elements in common. First of all, in the treatment of both diseases, non-pharmacological methods are very important. In diabetes, it is lifestyle and diet; in insomnia, it is sleep hygiene. The principles of sleep hygiene state that the bed should be used primarily for sleeping. We should not read, watch television, or eat in it. The bedroom should be dark, quiet, and rather cool – 18 to 20°C. Before sleep, we should not be very full or hungry; it is also worth avoiding caffeine, which is present not only in coffee but also in cola or chocolate. Two to three hours before going to bed, physical exertion is also not recommended, nor anything that arouses strong emotions. In the evening, we try to calm down. It is also important not to try to force sleep. If sleep does not come, it is better to get out of bed briefly, as staying in bed can create negative associations. It is better to get up, read a book, and after several minutes, try to lie down again. One should also not allocate too much time to sleep. Six, at most eight hours, is enough. It is also important to go to bed and get up at fixed times (also on weekends). Another thing – when we cannot fall asleep or wake up at night, we should not check what time it is, as this may additionally stress us and fuel insomnia.

Physical activity before sleep is not recommended, but what about during the day? 

It is very much recommended. It has been proven that areas of the brain controlling muscles active during the day sleep more deeply. This means that physical activity during the day improves sleep quality. 

Many people suffering from insomnia use over-the-counter herbal preparations or melatonin. Does this make sense? 

Herbal preparations have not been scientifically proven effective, and any benefit is likely due to the placebo effect. Melatonin, on the other hand, is not a sleeping pill. It is a hormone that our body secretes in the dark. Melatonin may be helpful in the treatment of circadian rhythm disorders, for example, jet lag, when we change time zones, or when we stay in subpolar regions. In our conditions, however, some effectiveness has been demonstrated in older people. This may be because circadian rhythm disturbances in older adults are linked to reduced functioning of the suprachiasmatic nucleus. 

Can psychotherapy be effective in treating sleep problems? 

Cognitive-behavioral therapy for insomnia is recommended as the primary method of treatment. It includes education about the purpose of sleep and the potential consequences of its deficiency. During sessions, patients also learn the principles of sleep hygiene and how to avoid worsening insomnia by focusing less on sleeping or not sleeping. The effectiveness of this method is very high, reaching 70–80 percent.

Is insomnia therapy provided individually or in group sessions?

It can be both individual and group-based. Group therapy is particularly effective. It involves patients with various problems sharing their experiences about which techniques work for them and what helps them. Such meetings are very supportive, reassuring, and helpful. However, not all patients take part in therapy – it is demanding work that requires patience and consistency.

It is much easier to take a pill. What medications are used for insomnia? 

It should be emphasized that we, as physicians, primarily talk to patients about non-pharmacological methods, and they are essential in the treatment of insomnia. However, of course, we also use pharmacotherapy. To improve sleep, we should definitely avoid chronic use of hypnotics, especially benzodiazepine derivatives. But if they are used, they should be taken on demand, and regular use should not exceed two weeks. For long-term use, sedative antidepressants may be prescribed. Sometimes antihistamines are also used, and in certain cases, for example, in elderly people with dementia, sedative neuroleptics.

Soon, we will be changing standard time to daylight saving time. Does this have any significance for the quality of our sleep? 

It does, especially for people suffering from insomnia. Such people become anxious about the time change, and this anxiety negatively affects their sleep. For them, the time shift is a revolution. It may intensify problems or cause a relapse of the condition. 
On the other hand, people who do not have sleep problems usually perceive the time change as an unpleasant fact to which they adapt. However, studies show that in countries with a climate similar to Poland, more accidents and heart attacks are recorded on the first day of daylight saving time. This means that losing even one hour of sleep can have negative consequences on the population level. 

Interview by Iwona Kołakowska
Photo by Michał Teperek
Office of Communication and Promotion, WUM