Asthma and the menstrual cycle…

Asthma is one of the most common underlying conditions to be worsened or triggered by the menstrual cycle. And yet, very few asthmatics are aware of how their cycle can affect them. Clinicians may also underestimate the impact of the menstrual cycle or contraceptive medications on asthma symptoms.

The incidence of asthma is massively affected by puberty. Considerable evidence suggests that asthma is more common in pre-pubescent boys compared to girls, but following puberty, a switch occurs, and asthma becomes more prevalent, and severe, in females.

For example, using 2012 health data from the US [fig 1], we can clearly see that nearly twice as many young males than females are affected up to age 14, then, after puberty, this pattern reverses. This sudden change in prevalence is likely linked to immunological factors, although, the exact cause is not yet known.

Asthma symptoms can worsen at certain points during the menstrual cycle. Research has found that ovulation and menstruation, can act as ‘triggers’ for attacks in some people. So, tracking your symptoms and identifying any pattern can help you to take preventative measures, reducing the likelihood, or severity, of an attack.

N.B. If you are asthmatic and suffer from period pain, be careful about which painkiller you take. Paracetamol is usually safe, but aspirin and non-steroidal anti-inflammatory tablets (NSAIDs) such as ibuprofen or naproxen may trigger an asthma attack in approx. 25% of asthmatics.

Irregular menstrual cycles may be linked to asthma, and allergies. A postal questionnaire survey of over 8000 Northern European cisgender women aged 25–42 found that those with irregular cycles (i.e., longer than 35 days on average) were about 50% more likely to have asthma symptoms and about 30% more likely to report hay fever, than those who said they had regular periods.

Age and reproductive life stage can affect asthma symptoms.

For example, approximately a third of pregnant asthmatics will experience a worsening of their symptoms, a third will see an improvement, and a third will see no change.

Interestingly, some research suggests that pregnant asthmatics carrying female foetuses might be more susceptible to severe asthma (it is speculated that perhaps this may be related to a spill over of foetal sex hormone into the parent’s circulation).

Around the menopause and perimenopause (the time leading up to the menopause), some people find that their symptoms get worse and some even develop asthma for the first time.

Testosterone acts as an anti-inflammatory, which reduces asthma symptoms in cis men until middle age, when their testosterone levels start to fall.

Female humans are more likely to develop asthma if they are obese, but not males. A Canadian longitudinal study, involving over nine thousand people, looked at the relationship between BMI and asthma. The authors concluded that obesity was related to development of asthma in cis women, but not cis men.

This is likely due to the interaction between testosterone and oestrogen with insulin, but the exact mechanisms remain unclear. However, it is known that weight loss can significantly alleviate asthma symptoms.

Symptoms are affected by contraceptive medications.

Contraceptive medications can cause asthma, or help improve symptoms, depending on the individual. This is indicative of the complex nature of the relationship between medications, the menstrual cycle, and asthma.

Quincy M.E.: “I think I’ve found the cause of your problem…”

Research has shown that HRT (Hormone Replacement Therapy), especially oestrogen-only, medication can be linked to an increased risk of developing asthma, as well as a worsening of symptoms, in some menopausal cis women.

There is still very little research available on the impact of HRT on asthma in transgender people. However, there is some anecdotal evidence that suggests (oestrogen-based) HRT medication may affect asthma and allergy symptoms, in either positive or negative ways, depending on the individual.