There is a little bit of light blood on the underwear should first be clear cause for targeted intervention, if the menstrual period, should be timely cleaning of clothing, if due to inflammation, should be targeted drug therapy. 1. The onset of menstruation: women in their daily lives, the onset of menstruation will be affected by a variety of factors, which may result in the early onset of menstruation. At this time, bloodstained underwear should be changed in a timely manner, and sanitary products should be used for timely treatment, and attention should be paid to personal hygiene at this stage. 2. Inflammation: including vulvovaginitis, vaginitis, cervicitis, etc., according to different situations, should be treated with appropriate medication, such as cephalosporin, metronidazole, etc., need to be under the guidance of a doctor to use medication. A little light blood on the panties may also have other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, give targeted treatment or treatment.