A woman's menstrual cycle affects the severity of respiratory symptoms, potentially worsening conditions such as asthma, a study suggests. Norwegian researchers studied almost 4,000 women, and found worse symptoms around ovulation. Writing in the American Journal of Respiratory and Critical Care Medicine, they said it may be possible to adapt women's medication. Asthma UK said it could help women with asthma manage their condition better. All the women studied had regular menstrual cycles lasting 28 days or less, and none were taking hormonal contraceptives. Of those studied, 28.5% were smokers and 8% had been diagnosed with asthma. Wheezing symptoms were worse between days 10 to 22 of cycles, with a slight dip near the point of ovulation for most. Shortness of breath was worse on days seven to 21, again with a slight fall around ovulation. The study found it was not just women diagnosed with asthma who experienced these symptoms and variations. Coughing was worse following ovulation for those with asthma, those who were overweight and smokers. When an individual woman has her period is determined by complex hormonal processes over the course of her cycle. Throughout, levels of different hormones rise and fall - and body temperature rises around ovulation. The researchers suggest that these fluctuations may have direct effects on airways. and indirect effects on inflammatory responses to infection.
