Introduction: Nasal stuffness is a great problem for many women in the later part of pregnancy. Objective: This study was performed to evaluate whether oestrogen causes nasal congestion and/or a hyperreactive reaction of the nasal mucosa. Material and Methods: Ten healthy fertile women were examined during menstruation. Nasal mucosal congestion was studied with rhinostereometry and acoustic rhinometry. The nasal mucosa was challenged with 3 doses of histamine solution to study nasal reactivity. Measurements were made 3 times during menstruation. To find the exact time of ovulation, when oestrogen reaches its peak value, intravaginal ultrasound tests were done and blood samples taken, to determine the oestrogen and progesterone levels. Results: The nasal mucosa became hyperreactive to histamine in connection with ovulation, when the blood level of oestrogen reached its peak. This does not occur during the menstrual or the luteal phase. No significant alteration was found in the baseline position during the menstruation. Conclusion: There is a connection between high oestrogen level and nasal mucosal reactivity.

Congestion of one side of the nose is accompanied by decongestion of the other side. This is called the nasal cycle. The nasal cycle does not seem to be present in all subjects and it has not been shown with rhinostereometry. There are very few studies showing whether there are spontaneous day-to-day variations in nasal mucosal congestion and no studies showing differences in nasal mucosal congestion between morning and afternoon. This, however, may be very important in studies covering a longer period. In the present study, data from four healthy volunteers were recorded 18 or 19 times in the mornings and afternoons on different days. Measurements were made with rhinostereometry, a peak flow meter (PNIF) and by symptom scores. A nasal cycle was found in some subjects. There was no difference in total nasal mucosal swelling in the mornings and in the afternoons and no day-to-day variation in the total nasal mucosal swelling.