Newly-divorced middle-aged women are more vulnerable to contracting HIV and other sexually transmitted diseases, a study reveals. It is because they tend to let their guard down with new sexual partners and avoid using protection since they are unafraid of getting pregnant, said study author Christopher Coleman, associate professor at the University of Pennsylvania School of Nursing.

Additionally, as ageing occurs, physiological changes due to menopause such as the thinning of vaginal walls make it more susceptible for a woman to contract a virus.

Medications that would be used to treat an STD or HIV become hard for a woman to tolerate because an ageing body metabolizes medications differently, a university statement said.

"There is a knowledge gap with women knowing what the physiological changes associated with menopause are," said Coleman.

"There is very little research on this subject and society and the government does not talk about it, but these high risk sexual behaviours need to be addressed because the rate of HIV-positive in middle-aged women is increasing," Coleman concluded.