Menstrual pain may be increased by smoking cigarettes, according to a new Australian study, the Daily News reported.
Smokers in the study were more at risk of experiencing painful menstrual cramps, with the pain increasing if they smoked more during the day than usual.
It's not clear why smoking cigarettes makes the pain worse, but it may be due to there being less oxygen available to the uterus, according to Dr. Jennifer Leighdon Wu, an OBGYN in New York City.
"We know that smoking causes vasoconstriction, or constriction of the blood vessels," said Wu, who wasn't involved in the new study. "When this happens with the uterus, it can cause pain."
The study followed 9,067 women for about 13 years. When the research started, the women were between the ages of 18 and 23. About 25 percent said they experienced painful periods, and a fourth were current smokers.
About 14 percent of the women had painful periods 70 percent to 80 percent of the time, which the researchers considered chronic.
The research also found that women who started smoking at a younger age were more at risk for painful periods. The risk was 59 percent higher for those who started smoking before age 13, and 50 percent for those who started smoking at 14 or 15.
"This study conveys some important messages that smoking may predispose women to repeated, distressing period pain immediately after menstruation and throughout their reproductive life, thus providing greater incentive for young women to abstain from smoking," Ju and colleagues wrote in their report.
Pain during period affects as much as 91 percent of women of child bearing years, according to Reuters.
