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Menstruation is your monthly period. During menstruation, your body releases hormones (special chemicals) to help prepare for pregnancy. As the levels of hormones increase, the lining of your uterus becomes thicker. During the middle of the menstrual cycle, ovulation occurs. Ovulation is when the ovaries release an egg. If the egg does not get fertilized, it passes through the uterus and out of the body. The lining of the uterus, together with blood and mucus, breaks down and sheds. This blood flow passes through the vagina and causes your monthly period.



  • NSAIDs , such as ibuprofen, help decrease swelling, pain, and fever. This medicine is available with or without a doctor's order. NSAIDs can cause stomach bleeding or kidney problems in certain people. If you take blood thinner medicine, always ask your healthcare provider if NSAIDs are safe for you. Always read the medicine label and follow directions.
  • Take your medicine as directed. Call your healthcare provider if you think your medicine is not helping or if you have side effects. Tell him if you are allergic to any medicine. Keep a list of the medicines, vitamins, and herbs you take. Include the amounts, and when and why you take them. Bring the list or the pill bottles to follow-up visits. Carry your medicine list with you in case of an emergency.

Follow up with your healthcare provider as directed:

Write down your questions so you remember to ask them during your visits.

When menstruation begins and ends:

Some girls may have their first period at 9 years of age, while others begin at 16 years or older. Most women start to have a monthly period at about 12 years. Menopause is the time in a woman's life when monthly periods stop. This usually occurs at age 50 or older.

What happens each month:

Each period may last for 2 to 7 days and can be light, moderate, or heavy. The total amount of blood loss may be 1 to 4 tablespoons (20 to 60 milliliters) for the whole menstrual period. This amount may be different among women and it may be different for you from one period to another. Your menstruation may be irregular for 2 to 3 years after your monthly period begins.

Symptoms during menstruation:

Premenstrual syndrome (PMS) is a group of physical, emotional, and mental changes that you may have before your monthly periods. These symptoms are caused by an increase in hormones. They include headache, dizziness, bloating, and nausea. You may also feel very tired, have breast swelling or soreness, and problems with sleep. You may have mood changes, such as feeling grumpy, sad, or emotional. These symptoms usually go away when your monthly period starts. Ask your primary healthcare provider for more information about PMS and how symptoms can be controlled.

Conditions that may prevent menstruation or make it irregular:

Your menstruation may be irregular for 2 to 3 years after your monthly period begins. Other things that can prevent menstruation or make it irregular are:

  • Pregnancy or breastfeeding: Pregnancy causes monthly periods to stop. A women who breastfeeds her baby full-time may not have a period until she stops breastfeeding.
  • Ovulation disorders: These include poorly-controlled diabetes, Cushing's syndrome, thyroid disorders, and other conditions that affect hormone levels. Polycystic ovarian syndrome (PCOS) is another condition that may cause irregular periods. When you have PCOS, your ovaries produce higher levels of male hormones than female hormones. PCOS may cause irregular menstrual periods.
  • Other causes:
    • Eating disorders such as anorexia (eating very little) or bulimia (bingeing and purging)
    • Weight problems, such as being overweight or underweight
    • Exercising too much
    • Previous surgeries on the abdomen or pelvis, such as surgery to remove the uterus
    • Stress or being emotionally upset

Self-care during menstruation:

  • Use tampons or sanitary napkins: Read the instructions carefully or ask how to use tampons or sanitary napkins.
    • Always wash your hands before you put in a new tampon to prevent infection. Wash your hands after you change pads or tampons.
    • Change your pad or tampon about every 3 to 4 hours to keep the blood from soaking through your clothes. Change your tampon often to help prevent toxic shock syndrome (TSS). This rare condition is caused by a bacteria and may be related to leaving a tampon in for a long time. Alternate tampons and sanitary napkins during the day. Use sanitary napkins at night. This may help prevent TSS.
    • Wrap toilet paper around the pad or tampon and throw it in the trash. Do not flush the pad or tampon down the toilet. It can block up sewer lines.
  • Rest, exercise, and eat healthy foods: These are some ways to help control symptoms of PMS. Your primary healthcare provider may also suggest other ways to manage PMS.

Contact your primary healthcare provider if:

  • Your period has not started within 3 years after your breasts develop.
  • Your period has not started by age 14 and you have excess hair growth on your body.
  • Your period has not started by 15 or 16 years of age.
  • Your period has not started and you exercise a lot or you have an eating disorder.
  • You have excess hair growth on your chin, face, upper lip, sideburns, chest, around your nipples, or lower abdomen.
  • You change sanitary napkins or tampons more than once every 1 to 2 hours.
  • Your periods used to be regular and then became irregular, or your period lasts for more than 7 days.
  • You periods occur more often than every 21 days or less often than every 45 days.
  • You have questions or concerns about your condition or care.

Return to the emergency department if:

  • You have severe abdominal cramps.
  • You have any of the following after using tampons:
    • Fever and chills
    • Diarrhea
    • Vomiting
    • Lightheaded feeling or confusion
    • A rash
    • Muscle aches

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.