Question: How do I count the days of my menstrual period? How do I distinguish between the days of my menstruation and dysfunctional uterine bleeding (istihada)?
In the Name of Allah, the Most Merciful and Compassionate
Before directly answering your question, it is best that we summarize the rulings of menstruation and dysfunctional uterine bleeding.
Menstruation (hayd) is the blood that exits from the uterus through the vagina of a female at least 9 lunars years of age. Its minimum is three days (72 hours) and its maximum is ten days (240 hours). [Shurunbulali, Maraqi al-Falah]
Any bleeding less than the minimum or more than the maximum is not menstruation, rather it is dysfunctional uterine bleeding (istihada). [Ibid.]
Dysfunctional Uterine Bleeding
Dysfunctional uterine bleeding is a vaginal bleeding that does not meet the requirements of being menstruation or the requirements of being lochia (post-natal bleeding). [Shurunbulali, Ascent to Felicity]
Distinguishing Between the Two
In order to distinguish between menstrual blood and dysfunctional bleeding, you must keep track of your habit.
Your habit is the length of your previous menstrual cycle. If your current cycle is different than the previous (and between the 3-10 days) this new number becomes your new habit. [Maydani, al-Lubab fi Sharh al-Kitab]
For example, if a woman has a five-day menstrual cycle, her habit is five days. If in the next month she sees seven days of bleeding, her new habit is now seven days.
If you know your habit, then any bleeding that exceeds your habit and also exceeds the maximum bleeding of 10 days – the amount of days commensurate to your habit is menstrual bleeding and the rest is dysfunctional bleeding. [Ibid.]
For example, if a woman’s habit is five days, and this month she has bled for twelve days – five days is menstruation and the remaining seven is dysfunctional bleeding. The bleeding exceeded her habit of five days and a maximum of ten days.
If you do not know your habit, then the ten days is menstruation and the rest is dysfunctional bleeding. [Ibid.]
How are the days counted?
The days are counted on the basis of hours, each day being 24 hours. Therefore, if your cycle begins at 11:53 pm, the first day is counted at 11:53 pm of the following day. [Ibid.]
I would strongly recommend taking a course in Islamic Law, especially the chapters of purification. Consider the courses offered here at seekersguidance.org. Also, I would recommend the book – Birgivi’s Manual Interpreted: Complete Fiqh of Menstruation & Related Issues.
I hope this helps,
Allah knows best.
[Shaykh] Yusuf Weltch
Checked and Approved by Shaykh Faraz Rabbani
Shaykh Yusuf Weltch is a graduate from Tarim; a student of Habib Umar and other luminaries; and authorized teachers of the Qur’an and the Islamic sciences