Evaluation of Changes in the Patency of the Nasal Cavity and Eustachian Tube Depending on the Phase of the Menstrual Cycle: A Pilot Study

(1) Background: Estrogen and progesterone, hormones specific to females, undergo fluctuations during the menstrual cycle. The aim of this study was to assess subjective and objective changes in nasal cavity and Eustachian tube patency depending on the phase of the menstrual cycle in two groups of women: those in a follicular phase group and those in a luteal phase group. (2) Materials and Methods: The study group consisted of 25 healthy non-pregnant women aged 24 to 32. Based on the phase of the cycle confirmed in sonography, they were divided into follicular phase (FP) and luteal phase (LP) groups. The Eustachian tube and nasal cavity patency examination was carried out using a SNOT-22 Questionnaire, a rhinomanometer, and a tympanometer. (3) Results: We observed that the incidence of nasal obstruction in SNOT-22 was significantly dependent on the cycle phase (<i>p</i> = 0.012) and was lower in the FP compared to the LP. Similar relationships were noticed between the cycle phase and the rhinomanometry outcome, where the LP was associated with a lower flow. We also revealed that the incidence of ear blockage significantly depended on the cycle phase (<i>p</i> = 0.001) and was lower in the FP compared to the LP. Women whose nasal patency deteriorated during the LP also had more negative pressure values in tympanometry. We observed that patients with negative PEAK L and R levels had a lower flow in rhinomanometry. (4) Conclusions: The results highlight the menstrual cycle's substantial impact on both subjective and objective nasal and Eustachian tube patency measurements. The novel finding in this study is that women whose nasal patency deteriorated during the luteal phase also had more negative pressure values in tympanometry. These results suggest that the deterioration of hearing during the menstrual cycle could be a result of swelling of the nasal mucosa and tubes.