Can stress give you a headache? Here are the cause-effect studies and therapies to manage it

Feeling under pressure at work, at school or in one's private life, and then finding oneself with a nagging headache: many people have experienced the connection between stress and a headache attack. But is this really the case? The most recent research confirms that stress is one of the factors most often reported by people with headaches, especially migraine and tension headache. A migraine is a throbbing headache, often localised on one side of the head, that may be accompanied by nausea, vomiting and sensitivity to light and sound. In some people, transient neurological symptoms may also appear before the pain, such as flashes of light or visual disturbances: this is the so-called 'aura'. Tension headache, on the other hand, manifests itself with a milder or moderate pain, of a constrictive type, like a tight band around the head, and is often related to muscle tension in the neck and shoulders.

The relationship between stress and headaches, however, is not the same for everyone: in some people stress seems to anticipate pain, in others the pain arrives when tension subsides, in others still the headache appears without an obvious link to stress.

Several studies have shown a link between stressful events and the onset of headaches, particularly migraine and tension headache. A study of over 20,000 female workers found that an imbalance between commitment and reward at work is associated with an increased risk of developing migraine. The same review also reports evidence of an association between stressful events experienced in childhood and an increased likelihood of migraine in adulthood, as well as an increase in cases of persistent migraine after mass traumatic events such as natural disasters or attacks. However, these are observational studies, i.e. they describe a statistical association between the two events, but a definite cause-and-effect proof is lacking. Most often, they speak of an unfavourable 'allostatic load', i.e. the cost to the body of adapting to repeated stressful events, or in even simpler words, the wear and tear the body undergoes if it remains under pressure for too long. When external demands exceed the body's ability to adapt, alterations in the hormonal, immune and nervous systems occur, which can contribute to the onset or worsening of symptoms such as headaches.

Many people claim to have a headache attack after a stressful day. Others, however, develop it at the weekend, when the tension eases. Some studies suggest that it is not so much the stress itself that causes the attack, but the change in stress levels. A sudden drop in tension can trigger the pain, in what is called a 'stress-release migraine'. At other times, the perception of stress may itself be an early sign of the attack, such as a craving for sweets or sensitivity to light: symptoms of the so-called premonitory period of migraine. In tension headaches, stress also plays a role, because it can contribute to the muscle tension that accompanies pain.

Not necessarily. According to a study of 1,200 patients, about 80 per cent of people with migraine report stress as a trigger. However, even in this case it is difficult to prove a cause-effect link that applies to everyone. There are people who never associate stress with attacks. Moreover, the relationship between stress and headaches may change over time, even in the same person. Some researchers believe that pain itself can be a source of stress, feeding a vicious circle in which anxiety, fatigue and tension worsen the quality of life and increase the frequency of attacks.