Menstruation

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Basics

• Summary
• Start Here
• Diagnosis and Tests
• Treatments and Therapies

Learn More

• Related Issues
• Specifics

See, Play and Learn

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Research

• Clinical Trials
• Journal Articles

Resources

• Reference Desk
• Find an Expert

For You

• Children
• Teenagers
• Patient Handouts

Summary

Menstruation, or period, is normal vaginal bleeding that occurs as part of a woman's monthly cycle. Every month, your body prepares for pregnancy. If no pregnancy occurs, the uterus, or womb, sheds its lining. The menstrual blood is partly blood and partly tissue from inside the uterus. It passes out of the body through the vagina.

Periods usually start between age 11 and 14 and continue until menopause at about age 51. They usually last from three to five days. Besides bleeding from the vagina, you may have

• Abdominal or pelvic cramping pain
• Lower back pain
• Bloating and sore breasts
• Food cravings
• Mood swings and irritability
• Headache and fatigue

Premenstrual syndrome, or PMS, is a group of symptoms that start before the period. It can include emotional and physical symptoms.

Consult your health care provider if you have big changes in your cycle. They may be signs of other problems that should be treated.

NIH: National Institute of Child Health and Human Development

Start Here

• All about Menstruation (For Teens) (Nemours Foundation) Also in Spanish
• Menstrual Cycle (Department of Health and Human Services, Office on Women's Health) Also in Spanish
• Menstrual Cycle: What's Normal, What's Not (Mayo Foundation for Medical Education and Research) Also in Spanish
• Menstruation and Menstrual Problems (National Institute of Child Health and Human Development) Also in Spanish
• What Are Menstrual Irregularities? (National Institute of Child Health and Human Development) Also in Spanish

Diagnosis and Tests

• Estrogen Test (American Association for Clinical Chemistry)
• FSH (Follicle-Stimulating Hormone) Test (American Association for Clinical Chemistry)
• How Do Health Care Providers Diagnose Menstrual Irregularities? (National Institute of Child Health and Human Development) Also in Spanish
• Menstrual Cycle Problems (American Academy of Family Physicians) Also in Spanish
• When You Visit Your Doctor: Irregular Menstrual Periods (Harvard Medical School)

Treatments and Therapies

• Black Cohosh (National Center for Complementary and Integrative Health)
• Chasteberry (National Center for Complementary and Integrative Health)
• Endometrial Ablation (American College of Obstetricians and Gynecologists) - PDF
• What Are the Common Treatments for Menstrual Irregularities? (National Institute of Child Health and Human Development) Also in Spanish
• What Are the Treatments for Amenorrhea? (National Institute of Child Health and Human Development) Also in Spanish

Related Issues

• Adenomyosis (Mayo Foundation for Medical Education and Research) Also in Spanish
• Bleeding Disorders in Women (Centers for Disease Control and Prevention)
• Delaying Your Period with Birth Control Pills (Mayo Foundation for Medical Education and Research) Also in Spanish
• Hormone Replacement Therapy: Can It Cause Vaginal Bleeding? (Mayo Foundation for Medical Education and Research) Also in Spanish
• Noncontraceptive Benefits of Birth Control Pills (American Society for Reproductive Medicine) - PDF
• Toxic Shock Syndrome (Mayo Foundation for Medical Education and Research)

Specifics

• Amenorrhea (Hormone Health Network) - PDF
• Amenorrhea (National Institute of Child Health and Human Development) Also in Spanish
• Female Athlete Triad (American Academy of Family Physicians) Also in Spanish
• Heavy Menstrual Bleeding (Menorrhagia) (Centers for Disease Control and Prevention)
• Menorrhagia (Heavy Menstrual Bleeding) (Mayo Foundation for Medical Education and Research) Also in Spanish
• Mittelschmerz (Mayo Foundation for Medical Education and Research) Also in Spanish
• The Facts on Tampons -- and How to Use Them Safely (Food and Drug Administration)
• What Causes Menstrual Irregularities? (National Institute of Child Health and Human Development) Also in Spanish

Clinical Trials

• ClinicalTrials.gov: Amenorrhea (National Institutes of Health)
• ClinicalTrials.gov: Menstruation Disturbances (National Institutes of Health)

Journal Articles References and abstracts from MEDLINE/PubMed (National Library of Medicine)

• Article: Sex differences in extinction to negative stimuli: Event-related brain potentials.
• Article: Systematic review of the clinical efficacy of vaginal progesterone for...
• Article: Correlation between Mechanical Properties of the Ankle Muscles and Postural...
• Menstruation -- see more articles
• Menstrual disorders -- see more articles

Reference Desk

• Female Reproductive System (Nemours Foundation) Also in Spanish
• Heavy Menstrual Bleeding (American College of Obstetricians and Gynecologists) - PDF
• Menstrual Cycle (Merck & Co., Inc.) Also in Spanish

Find an Expert

• Eunice Kennedy Shriver National Institute of Child Health and Human Development (National Institute of Child Health and Human Development) Also in Spanish
• womenshealth.gov (Department of Health and Human Services, Office on Women's Health) Also in Spanish

Children

• All about Menstruation (For Children) (Nemours Foundation) Also in Spanish
• Five Things Girls Want to Know about Periods (Nemours Foundation)
• Getting Your Period (Department of Health and Human Services, Office on Women's Health)
• Menstrual Problems (For Parents) (Nemours Foundation) Also in Spanish
• Pads and Tampons (Nemours Foundation) Also in Spanish
• Talking to Your Child about Menstruation (Nemours Foundation) Also in Spanish
• When Will I Get My Period? (For Kids) (Nemours Foundation) Also in Spanish

Teenagers

• Coping with Common Period Problems (For Teens) (Nemours Foundation) Also in Spanish
• Feeling Fresh (Nemours Foundation) Also in Spanish
• Female Athlete Triad (Nemours Foundation) Also in Spanish
• Irregular Periods (Nemours Foundation) Also in Spanish
• Medical Uses of the Birth Control Pill (Children's Hospital Boston)
• Menstrual Disorders (American Academy of Pediatrics) Also in Spanish
• Problem Periods (Department of Health and Human Services, Office on Women's Health)
• Toxic Shock Syndrome (For Teens) (Nemours Foundation) Also in Spanish
• Using Your First Tampon (Children's Hospital Boston) Also in Spanish
• Your First Period (American College of Obstetricians and Gynecologists) Also in Spanish
• Your Menstrual Cycle (Department of Health and Human Services, Office on Women's Health)

Patient Handouts

• Amenorrhea - primary (Medical Encyclopedia) Also in Spanish
• Endometrial ablation (Medical Encyclopedia) Also in Spanish
• Mittelschmerz (Medical Encyclopedia) Also in Spanish
• Secondary amenorrhea (Medical Encyclopedia) Also in Spanish