What should I do about the continuous bleeding after menstruation for a month, and my inability to distinguish between menstrual blood and istihadah (non-menstrual bleeding), given that I suffer from hypothyroidism?

A woman experiencing استحاضة (non-menstrual vaginal bleeding) has three scenarios:

1. The Beginner (Mubtada’ah): She observes the bleeding she sees as menstruation as long as it does not exceed 15 days. If it exceeds that, she considers herself menstruating for 6 or 7 days, determined through investigation and emulation of her relatives if she cannot distinguish (between types of blood). Otherwise, she acts based on differentiation (black blood or blood with an odor), provided it does not exceed 15 days.

2. The Differentiating Woman (Dhat al-Tamyiz): She differentiates between menstrual blood and استحاضة by color and odor. She refrains from prayer, fasting, and intercourse for the duration of the distinct blood. Then she performs ghusl (definition) (ritual bath) and prays, provided it does not exceed 15 days.

3. The Woman with a Known Habit (Dhat al-Aadah al-Ma'loomah): She observes her regular habit (menstrual period), then performs ghusl and ablution for each prayer when its time enters. It is permissible for her husband to have intercourse with her until the time of her habit arrives in the following month.