Because of a lapse in government funding, the information on this website may not be up to date, transactions submitted via the website may not be processed, and the agency may not be able to respond to inquiries until appropriations are enacted.

The NIH Clinical Center (the research hospital of NIH) is open. For more details about its operating status, please visit cc.nih.gov.

Updates regarding government operating status and resumption of normal operations can be found at OPM.gov.

Menstruation and Menstrual Problems

Menstrual irregularities are changes to the menstrual cycle that result in missed periods, irregular periods, or excessive bleeding. NICHD is one of many federal agencies and NIH Institutes working to understand menstrual problems. NICHD supports and conducts research on what causes menstrual irregularities and how best to treat and detect them.