A girl's first menstrual period.
Disclaimer: All information provided in this glossary is for educational purposes only. It is not intended as a substitute for advice provided by a medical doctor or qualified healthcare provider. You should not use this information for self-diagnosis or for treating a health problem or disease. If you have any questions whatsoever about your medical health or believe you have a medical problem or disease, you should contact your medical doctor or healthcare provider. You should never disregard medical advice or delay seeking medical advice or treatment because of something you have read in this glossary. No guarantee is made about the accuracy, completeness, or relevance of the information contained herein.