The following acts, when done knowingly and deliberately in the days of Ramadan, will invalidate the fast. In addition to being considered great sins, a person committing one of these acts will have to continue fasting the rest of the day that he/she committed it, and he/she is also required to take certain measures of reconciliation as indicated below.

　　1) Intentional eating and drinking

　　2) Sexual intercourse

　　3) Intentional vomiting

　　4) Poor intentions

　　 [Imam Al-Bukhari and Imam Muslim]

　　5) Injections containing nourishment

　　Involuntarily events that break the fast

　　Under this category there are two things that are related to women.

　　Even if such bleeding begins just before the sunset, the fast of that day is rendered invalid. A woman in this case will have to fast a day later for every day (or part of day) that she missed.

　　‘ath, may Allah be pleased with him who came and asked her "Why is it that the menstruating woman has to make up her fasts but not the prayers?" …‘Aa'ishah said: "That (menstruation) used to come upon us and so we were ordered (by the Prophet, to make up the fasts and were never ordered to make up the prayers." [Imam Al-Bukhari and Imam Muslim]