Women who struggle to breathe because of asthma symptoms are familiar with many of the triggers: exercise, pollen and cigarette smoke. But there is another trigger that might surprise you: hormones. Increasingly, researchers are finding evidence that hormones play a role in the development and symptoms of asthma.

Consider this:

• Asthma is more common among boys than girls during childhood. During puberty, the prevalence of asthma is about equal, then girls take the lead.
• Women are more likely to be hospitalized with symptoms or even die from asthma.
• Postmenopausal women who took hormone replacement therapy (HRT) were more than twice as likely to develop asthma as women who never used HRT.

Asthma is inflammation that constricts muscles in your airways, making it feel like you are trying to suck air through your fist. Symptoms include wheezing and coughing. Changes in estrogen and progesterone levels may cause more constriction of the airways, so your symptoms and treatment may change at different stages of your life.

Menstruation. Studies have shown that approximately a third of women with asthma report an increase in symptoms in the days leading up to and during menstruation.

• Keep a symptom diary to record how your periods affect your asthma.
• Talk to your doctor about adjusting preventive medication during your menstrual cycle.
• Be aware that using aspirin and other nonsteroidal medications to relieve cramping may increase asthma symptoms.

Pregnancy. Approximately a third of women with asthma found their symptoms improved during pregnancy, a third did not change, and a third say their asthma got worse.

• If your asthma symptoms grow worse, talk to your physician about adjusting your medication. Most asthma medications, including inhaled steroids, are safe to use during pregnancy.
• Uncontrolled asthma can cause serious medical problems for mother and baby, including premature birth.

Menopause. Studies suggest that taking steroid tablets continually or taking high doses of inhaled steroids for many years may increase the risk of osteoporosis in women after menopause.

• You can reduce the risk by using a spacer to take your inhaled steroid and rinsing your mouth out after taking your steroid inhaler.
• Take other preventive measures for osteoporosis, such as eating calcium-rich foods and doing weight-bearing exercise like walking or jogging.

Asthma treatments can be complicated by medications you are taking for other conditions. If you take other medications, talk to your doctor about the best way to treat your asthma.

Is It an Asthma Attack? Asthma attacks can vary in severity, from slight shortness of breath to respiratory failure.

• Shortness of breath
• Wheezing
• Dry cough, sometimes brought on by exercise
• A feeling of tightness in the chest