The Effect Of Progesterone On Breathing

Managing breathing for women is a complicated topic. For men, regulating breathing is primarily driven by CO2 tolerance and brainstem regulation. These two factors are present for women. However, for women, the hormones progesterone and estrogen significantly impact breathing. This influence exists during the menstrual cycle, pregnancy, menopause, and beyond. If women understand how these hormones work, they can adapt their breathing to suit the various stages of their menstrual cycle and life.

Progesterone (the focus of this blog) is a hormone primarily related to reproduction. It rises and falls during the menstrual cycle, helping to prepare the uterus for a fertilised egg. If there is a pregnancy, the levels of progesterone remain high. If there is no pregnancy, progesterone levels drop, triggering menstruation.

Another function of progesterone is as a respiratory stimulant. It acts on the respiratory centres in the brainstem. So, throughout a menstrual cycle, a woman’s breathing changes depending on her progesterone levels. Specifically, progesterone peaks during the luteal phase, increasing sensitivity to carbon dioxide (CO2). At that time, even a ‘normal’ level of CO2 can lead to an increased respiratory rate as the body tries to exhale excess CO2. In extreme cases, the level of CO2 in a woman’s blood can drop as much as 25% (more commonly, it is 10-20%) when progesterone peaks, which may also cause or exacerbate premenstrual syndrome.

Faster breathing often manifests as shallow upper chest breathing. There are two primary consequences of this. First, some of the nerves in our sympathetic nervous system (fight or flight response) are located in the upper chest. Shallow, rapid breathing can stimulate those nerves, causing spikes in cortisol and adrenaline. That can encourage more shallow, rapid breathing. Second, less CO2 in our blood means less vasodilation, i.e., poorer circulation. Less CO2 also impacts the Bohr effect, meaning a less efficient transfer of oxygen from blood into our cells. This affects everyday life, including athletic performance and concentration, as less oxygen is distributed to muscles and brain cells. Breath training (and slowing down) can help to lessen these effects.

Throughout pregnancy, progesterone levels remain high. This is the body’s way of ensuring that the unborn child receives sufficient oxygen, even if it means the mother is overbreathing. Because of this adaptation, breath training for pregnant women should only be undertaken with the supervision of a trained instructor.

For women going through perimenopause, menopause, or who are post-menopause, progesterone levels will drop below previous norms. The body still produces some progesterone, but only small quantities. The reduction of this breathing stimulant can have a significant impact on women. As a result, women may breathe shallower, producing a permanent effect similar to that experienced by some during the luteal phase. Feelings of breathlessness can lead to feelings of anxiety. Progesterone also affects the tone of the upper airways. A loss of tone can lead to snoring and, in some cases, sleep apnea.

Women need to be aware of their breathing and how their patterns change during their cycle and throughout their lives due to the effects of progesterone. The situation is dynamic and complex, and could take up a whole book. This blog is not intended as a comprehensive guide. What is known is that breath training can be an effective tool in helping women navigate these changes and avoid long-term health issues caused by poor breathing patterns, especially when progesterone levels are reduced long-term.

Disclaimer

This blog is for informational purposes only. It is not medical advice. Always consult a healthcare professional for personalized guidance and treatment.