MENSTRUAL CYCLES( MONTHLY PERIODS) What is a menstrual cycle? The menstrual cycle is the series of changes a woman's body goes through to prepare for a pregnancy. About once a month, the uterus grows a new lining (endometrium) to get ready for a fertilized egg. When there is no fertilized egg to start a pregnancy, the uterus sheds its lining. This is the monthly MENSTRUAL BLEEDING(also called menstrual period) that women have from their early teen years until menopause, around age 50. The menstrual cycle is more than just your period—it’s the rhythmic changes of the your reproductive system. The changes throughout the menstrual cycle are governed by hormones, which include estrogen, progesterone, follicle stimulating hormone, testosterone and others. They trigger the growth of follicles in the ovaries, the release of an egg (ovulation), and the growth and shedding of the uterine lining (the period) This shedding is the blood flow which occurs every month cyclically. ADULT CYCLE LENGTH A normal menstrual cycle length for an adult who is not using any form of hormonal contraceptive or IUD (CuT)usually is between 24 to 38 days . This means that an adult will have between 11 to 13 menstrual cycles per year. It is counted from the FIRST DAY OF YOUR LAST PERIOD TO THE FIRST DAY OF THE NEXT PERIOD. The length of your cycle can be affected by factors like stress, diet,  jet lag or exercise—anything that affects your reproductive hormones. to be continued----- dr nandini shete---- gynecologist