Menstrual abnormalities such as light, irregular or painful periods are more common for women living with HIV than among other woman, according to a recent study at the Nigerian Institute of Medical Research. The study recruited 627 positive women and 651 negative women between the ages of 18 and 41, and found that women with HIV experienced additional menstruation irregularities if their CD4 counts were below 200, if they had a low body mass index (BMI) or if they were not taking antiretroviral therapy.