TAKE A DEEP BREATH

BREATHING facts that may surprise you. this week: the time of the month can affect breathing

THE pattern of a woman’s breath can change throughout the menstrual cycle. In 2012, a Norwegian study of nearly 4,000 women — some with asthma — found wheezing worsened from days ten to 22 of their cycle, when oestrogen is rising. Oestrogen can cause fluid to collect in the tissues, narrowing airways, explains Dr Charlotte Rayner, a respiratory physician from Spire St Anthony’s Hospital in Sutton, South-West London. And breathlessness peaked as progesterone rose — progesterone lowers the threshold at which the body responds to carbon dioxide. So women may breathe faster as they try harder to expel that CO2.