In ancient times, Hippocrates described a headache resulting from “immoderate venery” (cited in [1]). Wolff, in his 1963 monography on headache (1963) (2), and accounts in the 1970s (3, 4, 5, 6, 7) drew attention to a benign form of headache occurring during sexual activity. The term “benign” implies a primary headache disorder not caused by a ruptured aneurysm or other intracranial disorders, which have to be ruled out by physical examination and by additional investigations (8).

In the first systematic description of the disease, 21 patients with this condition were reported (7). One subgroup of patients had pain that evolved slowly, which was possibly related to excessive muscular contraction of the neck and jaw muscles. A second, larger group of patients suffered a sudden onset of severe pain shortly before, at the moment of, or shortly after orgasm. Another publication described three patients with a third type whose pain resembled that of headache following lumbar puncture, suggesting that the latter headache resulted from a tear of the dura during sexual intercourse, leading to low cerebrospinal fluid pressure (6). The first edition of the IHS classification differentiated three types of headache associated with sexual activity (diagnoses 4.6.1 to 4.6.3): type 1 as a dull ache in the head and neck (7), which intensifies as sexual excitement increases; type 2 as a sudden severe (“explosive”) headache occurring at orgasm; and type 3 as a postural headache resembling the one caused by low cerebrospinal fluid pressure. It appeared, however, that type 3 is very rare and must be regarded as a symptomatic headache. Thus, in the second edition of the IHS classification, only type 1 and type 2 are defined (see Table 100-1).

In 1986, Johns (9) reviewed 110 published cases (24% type 1; 69% type 2; 7% type 3). With one exception (10), all subsequent publications concerned type 2.

The prevalence of headache attributed to sexual activity is unknown. In the only population-based epidemiologic study, the lifetime prevalence was about 1% with a broad confidence interval and similar to that of benign cough headache and benign exertional headache (11). Some authors believe that this headache is underestimated, since patients often feel embarrassed to report intimate details about their sexual activities (3). In cohort studies of headache clinics, it is estimated that patients with headache attributed to sexual activity account for approximately 0.2% to 1.3% of all headache patients (12, 13, 14).

The exact pathophysiology of headache attributed to sexual activity is unknown. There is no evidence that this headache type is primarily genetic, although a report
of a family with four affected sisters has been published (9).

Due to the nature of the headache, it has been suggested that type 1 is related to muscle contraction or tension-type headache (8,15,16). Some emphasize the similarity to primary exertional headache and postulate that a transient increase in intracranial pressure due to a Valsalva maneuver during coitus might play a pivotal role in the pathophysiology of type 2 (17,18). In three patients, segmental spasms of cerebral arteries had been observed in the days after the headache, but the changes were still present months after the first angiography in two of them (19, 20, 21), and in a series of nine patients no abnormalities of the cerebral vessels were revealed by angiography (7). Some authors emphasize a pathophysiologic relationship between type 2 and migraine (9,16,22) and a release of vasoactive substances such as neurokinins, serotonin, and catecholamines (4,6,16). However, these assumptions have been speculative and not based on clinical studies.

Heckmann et al. (23) suggested that patients with headache attributed to sexual activity had an impaired metabolic cerebrovascular autoregulation. This was confirmed by a study showing that under the condition of sexual excitement and other still unidentified factors, the cerebral vessel walls respond to pH decrease with impaired vasodilation compared with healthy subjects and migraineurs (24). In contrast to previous assumptions (25, 26, 27), arterial hypertension is not a major risk factor for headache attributed to sexual activity, since it is found in only 18% of the patients (14). However, patients with this type of headache show a higher increase of arterial blood pressure under physical stress (24).

Furthermore, it could be shown that patients with headache attributed to sexual activity have a loss of cognitive habituation during their bout (but not during the headache) similar to that known from patients with migraine (28). This finding was independent from the coexistence of migraine in these patients. However, a comorbidity of migraine or a positive family history both for migraine and headache attributed to sexual activity type 2 has been shown in several case series (9,14, 15, 16,26). The link between migraine and headache attributed to sexual activity has still to be elucidated.