Inclusion Criteria:

Aim 1 Inclusion Criteria for Clinical Registry (at Mayo Clinic):

• Include the screening hormones (eg, estradiol (E2) < 50 pg/ml, FSH<10 mIU/ml, and LH < 10mIU/ml and other HA-defining hormones); or clinical diagnosis of Hypothalamic Amenorrhea (HA) by medical providers.
• Premenopause status.
• Able to give informed consent.
• ≥ 18 and ≤ 40 years of age.

Aim 2 Inclusion Criteria for Nurse’s Health Study II Data (at Brigham and Women's Hospital):

• Women with a recorded age at menarche who were premenopausal at the time of menstrual cycle report will be included.

Exclusion Criteria: 

Aim 1 Exclusion Criteria for Clinical Registry (at Mayo Clinic):

• Psychotropic/illicit drug use.
• Medical/neurological/major psychological disorders (other than depression and anxiety).
• Parturition/lactating in the last 6-12 months.

Aim 2 Exclusion Criteria for Nurse’s Health Study II Data (at Brigham and Women's Hospital):

• Analyses will exclude women who report CVD events before study baseline.
• For risk factor endpoints, we will also exclude women reporting risk factors of interest at baseline.

Eligibility last updated 6/14/22. Questions regarding updates should be directed to the study team contact.