Introduction: The incidence of associate pathologies has been studied during the sleep, as well as the diagnostic efficiency of the clinical history.
Patients and methods: Patients (n = 136) remitted by diverse services, have been studied. It has been carried out a complete polysomnography, as well as other supplementary studies (anxiety and depression tests, excessive daytime sleepiness Epworth's test, EEG and sleep notebook).
Results: The most common symptom turned out to be the primary snores, followed by the excessive daytime sleepiness and apneas. The results of the excessive daytime sleepiness Epworth's test and the anxiety and depression tests were not useful to differ among pathologies, not even between pathologies and patients with normal sleep. The percentage of diagnosis of suspicion confirmed by the polysomnography was of 39.7%, while in 11% of the total of patients it was observed the existence of more than a pathology of the sleep. In 49.3% of the cases the polysomnographic diagnosis was completely different from the diagnosis of suspicion. Among the patients with clinic suspicion of apnoea, in 48.3% of the cases the existence of the same one was verified, although in 14.6% it was associated with other pathologies. In 51.7% of the patients it was not possible to confirm this pathology.
Conclusions: The clinical history is not enough for the diagnosis of the pathologies of the sleep. On the other hand, the existence of associate pathologies diminishes the value of several 'screening-methods'. Therefore, it is fundamental to carry out a complete polysomnography in all the patients that present any sleep disorder on the part of doctors that approach the problem of the sleep in a global way and not only thinking in the possible existence of syndrome of sleep apnoea.