Researchers have found that fluctuations in female sex hormones can play a major role in the development of asthma and allergies. The analysis of studies involving more than 5,00,000 women highlights a link between asthma symptoms and key life changes such as puberty and menopause.

"Asthma and allergy symptoms are often affected by life events such as puberty and menopause, but the reasons behind this are unclear," lead author of the study, Nicola McCleary from the University of Edinburgh, said.