Sarah Whitten
05.05.2025

Hormones and Your Breathing

Do you ever notice that your breath feels different as you move through your cycle? Or have you found your breathing changing while you go through perimenopause? Do you find your mood changing throughout your cycle or as you have entered perimenopause – an increase in anxiety, trouble sleeping etc.? It could be due in part to hormonal shifts and how those shifts are impacting your breath. Read on to discover more.

We often see changes in breathing arise at four specific times in bodies that menstruate: puberty/menarche, pregnancy, peri- and post-menopause. At each of these life phases there can be an uptick in issues like hyperventilation and asthma or even just swollen nasal passages, due in part, to hormonal changes.

Let’s begin with a review of the menstrual cycle

Menstruation often begins around age 12, but its onset could vary anywhere from ages 10-16.

Perimenopause, a time when cycles can begin to vary, can begin anywhere from the mid 30’s to late 40’s.

Menopause is a singular moment in time when one has gone for an entire year without a menstrual cycle. Once past that time, one is post-menopausal.

The menstrual cycle can be broken down into 4 distinct phases.

Phase 1: Menses – this accounts for days (approximately) 1-5, This is when your period happens and the thickened uterine lining is shed. Levels of estrogen and progesterone that have increased are not needed to sustain a pregnancy so they drop during this phase.

Phase 2: Follicular Phase – this accounts for days (approximately) 6-14. The body starts the process of preparing the uterus for pregnancy again. Ovaries release estrogen to start to thicken the lining of the uterus. The pituitary gland, located at the base of the brain releases follicle stimulating hormone (FSH) to trigger follicular growth in the ovaries, leading to an egg being produced.

Phase 3: Ovulation – this accounts for day 14 (approximately). At this time the pituitary gland releases luteinizing hormone (LH) and that triggers the follicle to release the mature egg. The follicle then transforms into a corpus luteum, a temporary gland that produces progesterone and estrogen to further help thicken the lining of the uterus.

Phase 4: Luteal Phase – this accounts for days (approximately) 15-28. The released egg travels down the fallopian tubes to the uterus. If it is fertilized by sperm it will implant in the thickened uterine wall. If it is not fertilized, as you reach the later end of phase 4, the corpus luteum begins to break down allowing levels of estrogen and progesterone to drop, allowing the lining of the uterus to stop thickening and the menses begin.

This 4 phase cycle continues until perimenopause when one’s ovaries slowly begin to march toward full retirement and they ramp back their production of hormones, causing irregularity in cycles and fluctuations in hormones.

The hormone I want to focus on in this post is progesterone. It is produced primarily AFTER ovulation and its primary role is in preparing the uterus to sustain a pregnancy. However it also has a role in our mood, sleep AND in our breathing.

A quick review of the biochemistry of breathing:

The most common way of thinking about breathing is that when we inhale, we take oxygen (O2) and when we exhale we expel a waste product, carbon dioxide (CO2). CO2 is a byproduct of breathing, but it is also an important regulator of O2 in the body.

You might remember from middle school biology that our lungs are made up of the

trachea,
bronchi,
bronchioles
alveoli

Here’s a good image of the lungs if you need a refresher.

When we breathe in O2, the alveoli, located at the end of the bronchioles, expand to take the O2 and move it from the lungs to the capillaries into our bloodstream. The alveoli then contract to pull CO2 out of the circulatory system and into the lungs where we then breathe some of it out.

Once in the arteries, O2 gets transported by red blood cells (hemoglobin) to be deposited in tissues around the body.

The ability of our tissues to receive O2 is actually dependent on having sufficient levels of CO2 in arterial blood.

When we hyperventilate, or over breathe, either at a chronic low level or a short term high level, CO2 levels can be driven down in the body. If CO2 levels are low the O2 bonds more tightly to hemoglobin and the result is sub-optimal oxygenation of the body and a cascade of symptoms can accompany this state. I’ve written before about Over Breathing and you can read that post here.

CO2 is more than just a waste product. It:

helps to regulate the pH in the body,
dilates smooth muscle (found in the walls of our airways),
helps to lower inflammation levels by reducing oxidative stress.

You might think it is our need for oxygen that drives our need to breathe. But actually it is our CO2 levels that govern our breathing. As CO2 levels rise in our bloodstream, chemoreceptors in the medulla oblongata in the brain read that input and trigger breathing. The medulla oblongata also relays information based on CO2 levels to the Autonomic Nervous System – which is what governs our fight or flight and rest and digest responses. When we aren’t comfortable having slightly higher CO2 levels in our blood, the brain says ‘breathe more so we get some of the CO2 out.’

In her book Restoring Prana, Robin Rothenberg refers to the Medulla Oblongata as the respiratory thermostat (p 81). Just like a smart thermostat predicts the temperature for your house based on how you have set it in the past, the MO sets our respiratory rate based on our most predominant breathing pattern and adjusts as we do things like movement.

We can train our body to become more tolerant to higher CO2 levels.

Let’s pull this back to hormones

We have estrogen and progesterone receptors throughout the body, including in our brain and in our lungs. Progesterone receptors have been shown to have a role in lung development and function. Some research has shown that as hormones cycle throughout the month the function of the lungs also fluctuates(https://pmc.ncbi.nlm.nih.gov/articles/PMC2731807/). Because the number of blood vessels in the lungs are changing as hormones change, the way the exchange of O2 and CO2 occurs at the level of the alveoli, as described above, changes as well.

Progesterone is considered a respiratory stimulant, meaning it increases the rate at which we breathe, causing us to breathe out more Carbon Dioxide (CO2) and have an increased sensitivity to CO2.

From days 10-22 of the menstrual cycle, progesterone is increasing in the body. This increase can account for up to a 25% drop in CO2 levels in the body (Chaitow p 190) and an even lower drop during pregnancy. We see the change in breathing pattern through a faster breath that can also cause greater motion in the upper shoulders/collarbone/neck region – where we breathe when our fight or flight response is triggered.

As we begin to breathe more due to increased progesterone, we breathe out more CO2. That drop in CO2 increases our sensitivity to its accumulation and can bring with it increased symptoms of PMS, anxiety, poor sleep, lowered sex drive, fatigue, headaches, menstrual migraines, greater instances of asthma and even panic.

For many this is occurring on top of an already altered breathing pattern where we are living with chronic low level hyperventilation due to living with chronic low level stress punctuated by periodic high stress experiences.

Almost every expert will be quick to point out, there is an alarmingly low amount of research done on women’s health. So there is much we still don’t know and need to learn more about.

What about Perimenopause and Menopause?

When we enter perimenopause levels of hormones begin to fluctuate and as ovaries begin to move into dormancy, we no longer have consistent progesterone pushed out into our system.

Despite being a respiratory stimulant, progesterone is also thought to have a role in strengthening the muscles at the back of the throat. The loss of progesterone in perimenopause is a possible contributor to why those muscles lose tone and we can begin to experience upper airway collapse, sleep disordered breathing and sleep apnea.

In his book The Breathing Cure, Patrick McKeown, founder of Oxygen Advantage (I hold a certificate as a Functional Breathing Instructor from OA) cites a study that indicates there is 200% increase in risk of sleep apnea in perimenopause due in part to hormonal changes (p316). Other contributing factors to apnea are loss of tone in the tongue and increased fat deposits in the tongue, throat/neck and belly.

When one uses menopausal hormone therapy, and progesterone is either taken daily or cyclically for 12 days of the month you may also feel breathing changes.

So what can we do now?

Our breathing can either serve to augment what is happening in the body as hormones shift or it can help to mitigate it.

One of the first actions you can take is to assess your BOLT score. BOLT stands for Blood Oxygen Level Test. The BOLT test tells us a lot about your baseline stress level and how tolerant you are to CO2

How to find your BOLT* score

Sit comfortably and relax for 5-10 minutes
Take a normal breath in and a normal breath out
At the end of your exhale, gentle close the nostrils and start a timer
Hold your breath out until you feel your first urge to breathe and stop the timer.

*if you have a history of asthma, or other known lung issues, please assess your BOLT score while working with a trained breathing instructor.

BOLT results:

Below 10 seconds: your everyday breathing pattern is likely irregular and noisy. You are very sensitive to CO2 accumulation.

10-20 seconds: your everyday breathing is somewhat compromised and your sleep could be more restful. You may notice issues with your energy concentration levels during the day.

20-30 seconds: your everyday breathing is probably quiet, calm and effortless.

30+ seconds: you have a high tolerance for CO2 accumulation and can likely exercise at higher thresholds while breathing through your nose.

Armed with your knowledge of your BOLT score you can begin to create a baseline functional breathing practice working toward breathing light, slow and low, and steadily increasing your BOLT score over a period of weeks to months.

The right approach to breathing will be highly individual depending on where one is in their hormonal journey and is also impacted by past history of trauma and experiences with fitness, as well as typical daily habits.

Things an individual can do to explore breathing include:

1. Find an optimal resting position for the tongue while doing passive breathing.

Say the word ‘Boston’ and notice where the tip of the tongue lands on the /n/ sound. Leave the tip there and allow the rest of the tongue to rest up against the hard palate. Keep your teeth slightly apart and allow the lips to come together. When this is not your habit it is often uncomfortable at first and may also be impossible if you have a tongue tie.

2. Close your mouth and breathe through your nose. While you are just passively breathing or doing things like taking a walk, work towards only breathing only through your nose. This can feel challenging if your habit is breathing through your mouth. Mouth breathing will mean lower CO2 tolerance and accompanying swelling of nasal passages as well as added risk for sleep breathing issues.

Here is a trick to help open up your swollen nasal passages to make them feel more comfortable to breathe through:

Breathe in and out, then pinch your nose closed at the end of exhale. Holding the breath out and with the nose blocked off, slowly nod your head 10-15 times. Release the nostrils and slowly breathe in. Repeat as needed.

3. Strengthen your Tongue! Keeping muscles of the upper airway strong helps prevent breathing problems while we sleep. Tongue exercises are simple and can be done easily every day.

4. Engage in training to work up to breathing light, slow and low.

Breathe Light means a silent, light breath in through the nose creating an improvement of blood flow and delivery of O2.

Breathe Slow means slowing down the rate of breath in and out, bringing a more balanced state of mind.

Breathe Low means focusing on the motion in the body happening in the region of the lower ribs and belly on inhale and exhale, creating an increase in the ability to focus our attention.

Together Breathe light, slow and low means training the body to have a better tolerance to CO2 levels and positive changes to our mental and physical state and improved sleep.

Having the ability to breathe this way will help offset the changes created by hormonal shifts throughout your cycle and across your lifespan.

To engage in breathing classes with Sarah Whitten Voice and Movement, please visit our Breathing Classes Page. If you would like to work 1-on-1 to have a custom designed breathing program, please set up a Discovery Call.