What came first? On sleeping problems and tension-type headache

If you sleep badly, you have a higher risk of getting headaches. At the same time, headaches often bring about sleeping problems. It is undisputed that both headaches and bad sleep influence each other, but it is not quite so easy to determine which came first. In this article, we will be investigating which direct links can be made between sleeping problems and tension-type headache.

What exactly is “sleep”?

Sleep is defined as a particularly deep state of bodily rest, during which many bodily functions are carried out more sparingly than when we are awake. For example, breathing, pulse, and brain functions are all reduced. Although the question of why we need to sleep has not yet been conclusively researched, we can assume that sleep is very likely to help the body’s recovery and healing. This assumption is supported by the fact that, for example, long-term sleep deprivation impairs our immune system.

Sleep is generally closely linked to our wellbeing and also affects the occurrence of headaches. Not only the duration, but also the quality of our sleep is significant here. Do you keep waking up at night, or can you sometimes never relax, is your breathing uneven or accompanied by loud snoring? All these factors play a role when it comes to whether we are waking up refreshed and rested in the mornings and starting the day full of energy, or whether we feel exhausted and can barely get out of bed.

Does bad sleep lead to headaches?

Tension-type headache, as it is correctly referred to, is the most commonly occurring type of headache. However, in comparison to migraine, it has always received less attention from researchers – potentially precisely because it is so widespread; many see it more as an everyday accompanying symptom than as an independent disorder.

Sleeping problems are described as a powerful trigger for tension-type headache in many scientific investigations. For the most part, they are the starting point for occasional, so-called episodic headache. However, if you are sleeping badly over a long period of time, there is a risk that the episodic headaches could develop into chronic ones – a development from which it can sometimes be hard for patients to recover. According to estimates from the International Headache Society (IHS), up to 3 per cent of the population suffer from chronic tension-type headache. For those affected, it is a significant hindrance to their working day and leisure time. Moreover, chronic headache is associated with the development of mental illnesses such as anxiety or depression.

Sleeping problems and tension-type headache: a bidirectional relationship

A whole range of different phenomena fall under the umbrella term “sleeping problems”. For example, they include snoring, bruxism (grinding your teeth; see “Grinding your teeth and headaches – which is the chicken, and which is the egg?”), or sleep apnoea, the temporary suspension of breathing during sleep.

Interrupted sleep and and tension-type headache have a bidirectional relationship. This means that both issues each affect the other. The analytical problem is: sleeping problems often occur in patients with headache, and on the other hand people with headache often complain about sleeping problems. This situation makes researching occurrences in this field particularly difficult. All the causalities at work must be defined and distinguished between in a particularly clear-cut manner, to avoid simultaneously proving everything and nothing. In a review paper, the Korean neurologist Soo-Jin Cho pays special attention to the circumstance of bidirectionality; she believes it is possible that these mutual dependencies of disease phenomena point to common, underlying pathophysiological mechanisms.

Sleep apnoea – when breath stops during sleep

Sleep apnoea refers to a temporary absence of breathing activity during sleep. Between two and four per cent of the population are affected by this, though the true figure is presumably much higher. For many patients, this respiratory disturbance causes a headache when they wake up in the morning. The mechanisms behind the phenomenon have become the subject of countless studies. An American research group was able to demonstrate a dose dependence: the more often the patients experienced sleep apnoea and the longer the breathing interruptions lasted, the more severe the headache in the morning would feel. Alberti and co-workers examined patient collectives, of which one was affected by insomnia and the second by sleep apnoea. It was discovered that, in both groups, around half of the participants reported morning headaches. In the group affected by breathing interruptions, the headache was rated as particularly severe. Similar connections have been reported in relevant studies from Europe and Asia.

Morten Engstrøm from the University of Trondheim brought an interesting hypothesis to the discussion. He posed the question of whether, due to inherited factors, patients with tension-type headache possibly require more sleep than those not affected by it. Should this be true, even small sleep disturbances and deficits could have far-reaching consequences, particularly for these people – including headache attacks.

The physiological consequences of apnoea

Through the respiratory standstills, the blood’s nightly oxygen saturation is lowered, while its carbon dioxide levels rise. The increased CO2 levels in the blood create a wakeup reaction, which causes breathing to start again. Sleep apnoea can be particularly demanding for the cardiovascular system because, despite varying blood oxygen levels, it must keep the supply constant and therefore carry more blood to the organs accordingly. Therefore, sleep apnoea also increases the risk of cardiovascular diseases, heart failure, heart attack, and stroke, among other things.

In a comprehensive study, the so-called “Cleveland Family Study” with more than 2,200 participants, it was shown that there is a causal link between the nightly undersaturation of the blood with oxygen and the occurrence of headaches when waking up in the morning.

Are there therapeutic possibilities?

One possible way to counter headaches when waking up is treatment with a breathing mask, the so-called BIPAP-ventilation (Bi-level Positive Airway Pressure). The patient receives breathable air through the mask under slightly increased pressure; for most affected people, this prevents respiratory standstills and improves sleep quality. In many cases, this also makes the morning headaches go away. However, many people find wearing a breathing mask while sleeping uncomfortable, meaning that it is frequently the last resort for relieving the symptoms.

Good sleep prevents headaches

If the number of research papers written on a  topic allows us to infer its importance for us humans, then it becomes clear how important good, uninterrupted sleep is for our wellbeing. Presumably, this is because our organism goes through a tremendous number of processes while we sleep, enabling it to function perfectly time and again throughout the day (see also the article “The brain – a real night worker”).

The taking in and processing of new sensations, concentrated learning, sports, animated conversations – all these activities have one thing in common: after seven to eight hours of restful sleep and with a refreshed mind, these kinds of exertions are easy to manage – and allow us to sink into a relaxing sleep in the evenings. If you would like to find out how sleep rhythm and quality affect your own experience of headaches, you can document your sleeping habits. This can be done, for example, with help from a sleeping journal or with the Headache Hurts App, which also documents individual headache occurrences as well as sleep and other factors relevant to headaches. This way, users can find out what the connection between sleep and headache episodes is for them personally.