Stress is a strange phenomenon which we all discuss, but don’t really do anything about - like the weather

Stress may be the most frequently mentioned trigger for migraine. 'That’s probably because s/he has been stressed', we often say when one of our friends suffers from migraine. 62% of migraineurs in a study believed that their migraine happened most often because of stress (Robins 1994). Nonetheless there are only a few studies that actually show any connection between stress and migraine (Galiano with various co-workers, 1995).

But what is stress? We all know what it means to be stressed; when everything happens too fast, we have to do something that’s more or less impossible, and someone is pressurising us. In a purely technical sense, stress is better defined. Stress happens when we experience something that influences (stresses) the organism more than normally. Stress can be purely physical – e.g. cold stress or stress because of tiredness, hunger or thirst; or stress can be psychological, if we have to live up to something we don’t really believe we can manage. Stress can also be released by sorrow, anger or uncertainty.

So stress is many things, but J. R. Fozard from the drug company Sandoz writes (1995) that stress in every case has a feature in common, namely our physiological reaction. When we are stressed, the nerve cells known as 5-HT2B and 5-HT2C-receptors release the chemical nitrous oxide (NO), which in turn acts on other nerve cells which make us feel pain because of a sterile inflammation in various blood-vessels in the brain, and so we get migraine.

Dr. Fozard is not the only one who has a theory about how we get migraine from stress. Theoharides and various fellow workers from Tufts University School of Medicine in Boston explain that stress activates some special cells in the brain, called mast cells. So mast cells should have some function in causing migraine.

Holm, Bury and Suda from the University of North Dakota have studied how women have a greater tendency to get stress migraine around the time of menstruation, and found that women themselves felt they have a tendency to feel more stressed and thereby get more migraine just before they menstruate. They give no biochemical explanation

In the journal Headache (November 1997) psychologists Holm, Lokken and Myers from the University of North Dakota wrote about 20 healthy female students who had migraine. The students were asked to keep a detailed diary about everything they did, and to note whether they had migraine and how bad it was. Everyday doings and occurrences had been classified into 58 stress classes. It was found that 14 of the 20 students got migraine at least once during the 2 months after a stressful experience. 4 of the students got migraine whose intensity depended on how stressed they had been, while one apparently got less migraine after a lot of stress. There was also a connection between having migraine and being stressed. 11 students reported that they were more stressed when they had migraine, and there was also a connection between the intensity of the migraine and the level of stress.

In one of the odder byways of stress-studies, Bell and various co-workers wrote that older people with migraine who themselves feel that they had a stressful youth, have a tendency to be more sensitive to smells than equivalent people who do not feel that the had an especially stressful youth.

In popular folklore there is a tendency to assert that migraineurs react more strongly in a stressful situation than non-migraineurs. In the report of a study where migraineurs and non-migraineurs were put into situations where they should solve unexpected problems immediately, Kroener-Herwig, Fritsche and Brauer from Düsseldorf in Germany wrote that they could find no difference in the reactions of the two groups.

In a similar way, Passchier, Goudswaard and Orlebeke from Rotterdam found that migraineurs and non-migraineurs generally react in the same way to e.g. an examination. Nonetheless migraineurs’ pulse rates rose less than those of non-migraineurs in the exam situation.

Finally, Birthe Krogh Rasmussen from the County Hospital in Glostrup, Denmark writes that the commonest triggering factors for migraine among Danes is stress and mental tension, but gives no clear definition of stress.

If you would like to read more about stress and migraine:

R. Bell, G. E. Schwartz, D. Amend, J. M. Peterson and W. A. Stini, 1994. Sensitisation to early life stress and response to chemical odors in older adults. Biological Psychiatry 35, 857-863.

J. R. Fozard, 1995. The 5-hydroxytryptamine-nitric oxide connection: the key link in the initiation of migraine? Arch-Int-Pharmacodyn-Ther. 329, 111-9.

L. Galiano, I. Montiel, R. Falip, M. Asensio and J. Matias-Guiu, 1995. Stress as a precipitating factor in migraine. Rev-Neurol. 23, 830-2.

J. E. Holm, L. Bury and K. T. Suda, 1996. The relationship between stress, headache, and the menstrual cycle in young female migraineurs. Headache 36, 531-7.

J. E. Holm, C. Lokken and T. C. Myers, 1997. Migraine and Stress: A Daily Examination of Temporal Relationships in Women Migraineurs. Headache 37, 553-558.

B. Kroener-Herwig; G. Fritsche and H. Brauer, 1993. The physiological stress response and the role of cognitive coping in migraine patients and non-headache controls. Journal of Psychosomatic Research 37, 467-480.

J. Passchier; P. Goudswaard and J. F. Orlebeke, 1993. Abnormal extracranial vasomotor response in migraine sufferers to real-life stress. Journal of psychosomatic Research 37, 405-414.

B. K. Rasmussen, 1993. Migraine and tension-type headache in a general population: Precipitating factors, female hormones, sleep pattern and relation to lifestyle. Pain 53, 65-72.

L. Robbins, 1994. Precipitating factors in migraine: A retrospective review of 494 patients. Headache 34, 214-216.

T. C. Theoharides, C. Spanos, X. Pang, L. Alferes, K. Ligris, R. Letourneau, J. J. Rozniecki, E. Webster and G. P. Chrousos, 1995. Endocrinology 136, 5745-50.