As sexy as thongs and G-strings can be, they could cause quite nasty vaginal infections.
G-strings encourage bacteria to spread from your bum to your vaginal area which might lead to infections.
The most common type of infections that thongs might spread include thrush and bacterial vaginosis and you sure don't want those.
"Try and make sure the crotch is cotton, synthetic underwear increases the moisture trapping in that area because it is not breathable," Dr. Vanessa Mackay, a spokeswoman for the Royal College of Obstetricians and Gynaecologists told The Sun.
"If there is more moisture there is more risk of bacterial infections and yeast infections because they thrive in that environment.
"You might want to think about using non-perfumed or hypoallergenic washing powder as well.
"And thongs may increase your risk of irritation and, in theory, there is a risk of bacteria from your back passage to your vagina," she said.
The doctors say that sleeping without underwear may be beneficial to women with vaginitis, which is inflammation of the vagina, and those who suffer from thrush, a common yeast infection.