niddah

Niddah, in Jewish law, refers to a woman’s state of ritual impurity within the system of family purity (taharat hamishpacha). The state is defined by rabbinic interpretation of biblical laws and applies to menstruation as well as certain other discharges. The term is commonly used to describe the period when a woman is not ritually available for marital relations.

Practices and timing vary by tradition, but in traditional Orthodox practice the period begins with the start of menstrual bleeding and continues through the end of the bleeding, followed by seven days in which there is no bleeding. During niddah, marital relations are prohibited and there are rules governing physical contact. If bleeding resumes during the count, the seven clean days are reset. After completing the seven clean days, the woman immerses in a mikveh, a ritual bath, and is then considered ritually pure, allowing marital relations to resume. The process is known as taharat hamishpacha.

The mikveh immersion is a key element of ending niddah and typically requires a ritually valid immersion pool and proper intention. Observance of these laws varies significantly. Orthodox communities tend to follow strict rules and timing, Conservative communities observe many of the same laws with variations, and Reform and some other groups may treat the laws as non-obligatory or less prescriptive. In addition to menstruation, certain other types of bleeding, such as postpartum or illness-related discharge, can also place a woman in a state of niddah under classical law, though modern practice varies.

The concept of niddah has deep historical roots in biblical and rabbinic literature and remains a focal point of the broader framework of Jewish ritual purity and marital life.