Inclusion Criteria:  Cohort 1:  Women may enter the cohort if they are between 11 and 55 years old and have a continuous observation of 365 days after the start of the observation period (from January 1, 2000 to December 31, 2020). Cohort entry events are limited to the earliest event per person. Entry events having no procedure occurrences of hysterectomy, starting anytime on or before cohort entry start date. Entry events having no condition occurrences of natural or iatrogenic menopause, starting anytime on or before cohort entry start date.  Cohort 2:  Women between 11 and 55 years old with continuous observation of 365 days before event may enter the cohort when observing a condition occurrence of HMB for the first time in the person's history; starting between January 1st, 2000 and December 31st, 2020. Cohort entry events are limited to the earliest event per person. Entry events having no procedure occurrences of hysterectomy, starting anytime on or before cohort entry start date. Entry events having no condition occurrences of natural or iatrogenic menopause, starting anytime on or before cohort entry start date. Entry events having no condition occurrences of gynaecological bleeding other than HMB, starting anytime on or before cohort entry start date.  Cohort 3:  - The cohort entry events, index date, and exit events are identical to those defined for cohort 2. Inclusion criteria is as defined for cohort 2, plus adding entry events having no condition occurrences of underlying causes of HMB, listed in 9.2.4.2 Underlying causes of HMB and including polyps, adenomyosis, leiomyoma, malignancy and endometrial hyperplasia, coagulopathy or iatrogenic HMB, starting anytime before or after cohort entry start date.  Cohort 4:  - The cohort entry events, index date, and exit events are identical to those defined for cohort 2. Inclusion criteria is defined as for cohort 2, plus adding entry events having a prescription for LNGIUD or a procedure occurrence of LNG-IUD placement, starting anytime after cohort entry start date.  Cohort 5:  - The cohort entry events, index date, and exit events are identical to those defined for cohort 2. Inclusion criteria is defined as for cohort 2, plus adding entry events receiving a prescription for, or a procedure occurrence of a guideline treatment (e.g. a prescription for LNG-IUD or a procedure occurrence of LNG-IUD placement), starting anytime after cohort entry start date.  Cohort 6:  - The cohort entry events, index date, and exit events are identical to those defined for cohort 2. Inclusion criteria is defined as for cohort 2, plus adding entry events of not receiving a prescription for, or a procedure occurrence of a guideline treatment (e.g. a prescription for LNG-IUD or a procedure occurrence of LNG-IUD placement), starting anytime after cohort entry start date.  Cohort 7:  - The cohort entry events, index date, and exit events are identical to those defined for cohort 2. Inclusion criteria is defined as for cohort 2, plus adding entry events of receiving a diagnosis of endometrial hyperplasia, or endometrial or cervical cancer anytime time prior to or after cohort entry start date.  Exclusion Criteria:  - None.