Around the age of 12, the first menstruation (menarche) occurs, and menopause, the final cessation of ovarian function, occurs at approximately the age of 50. This is the reproductive period of a woman. Usually, the menstrual cycle begins with the first bleeding and ends by the first day of the next period. On average, it lasts 28 days, and it is normal for its duration to be between 21 and 35 days. Usually, during a cycle, a few teaspoons of blood, parts of the uterine lining, vaginal secretions, endometrial cells and bacterial flora are released. Normal blood loss per day is 10 to 35 ml, and 60 ml of blood is considered heavy bleeding. Each month during menstruation, the color of the blood may vary, from pink to brownish. Up to about 15-16 years of age, it is normal for the bleeding to have a dark red or brownish color. It is possible for the same feature to occur incidentally in the reproductive years as well as during menopause. What does the color change depend on? Pink shades are a sign that the first day of menstrual bleeding is coming. Blood has a bright red color and when mixed with vaginal secretions it can turn pink. If the bleeding is not profuse, it is also possible to have pinkish hues. Bright red blood indicates that the blood is fresh and has not been retained in the uterus. It begins to be released profusely during the first few days of menstrual bleeding. Dark red blood may be accompanied by clots. This is also considered normal as long as the clots are not very large. Its color is darker because the blood stayed longer in the vagina. Brown blood is observed towards the end of the menstrual cycle. When should medical attention be sought regarding the menstrual cycle? Normally, menstrual bleeding should last 4 to 7 days. If its duration is longer, if full bandages are changed every two hours or if very strong pains appear in the lower abdomen, an obstetrician-gynecologist should be consulted. Other indicators indicating the need to consult a doctor are: In case of bleeding outside of menstrual bleeding; With an irregular cycle; When feeling tired and dizzy; In case of an unpleasant or fetid smell; When menstruation is accompanied by fever; There are strong urges for nausea and vomiting, etc.