Breath of Fresh Air: Feature Articles

Chapter 35: Is it true that in some women asthma can worsen around the time of the menstrual period?

It is true for some women, but certainly not all, that their symptoms of asthma — and their breathing capacity as judged by their "peak flow" measurements — may worsen predictably each month during the days immediately before and during their menstrual period. In a scientific study recently reported in a medical journal, among women requiring medical care in an Emergency Department for attacks of asthma, an unexpectedly large percentage said that their asthmatic attack developed around the time of their period.

It is difficult to know what aspect of the hormonal changes that occur in the days around the time of the menstrual period accounts for increased symptoms of asthma, and why these changes affect some women but not others. Perhaps it is the rapid changes in estrogen level, from high to low, that occurs around this time of the month; perhaps other hormones play an equally important role. Two other observations about asthma and women's hormone levels make it likely that in some women they can have an important influence on asthma.

One observation is that during pregnancy, asthma can significantly worsen in some women (in 20-30% of asthmatic women). Among other women, pregancy has no influence on their asthma, and among still others their asthma significantly improves during pregnancy. It is possible that the large hormonal changes taking place during pregnancy may be a cause for these changes in asthma severity during pregnancy.

The other interesting observation is that after the menopause a new diagnosis of asthma is made more frequently among women who take hormone replacement therapy (estrogen hormones) than among women who do not. The longer the duration of hormone replacement therapy and the higher the dose, the greater the likelihood (although it is still small) that one will newly develop asthma.

More research needs to be done to help us understand the relationship, in general, between gender and asthma and, in particular, between varying levels of female hormones and control of asthma in some women. Meanwhile, a variety of strategies can be used to minimize the impact of the menstrual cycle on asthma. If you think that this might be an issue for you, mention it to your doctor. The best way to begin to deal with the topic is to bring it up for discussion.