It is difficult to provide a precise definition of "light flow" versus "heavy staining." If you feel a hargashah (learn more here) or actually see blood exiting your body, you would be in niddah. Otherwise, as a rule of thumb, discharge that could easily be contained by one standard disposable pantyliner over the course of a day is considered spotting and is subject to the leniencies of stains. Heavier bleeding is typically considered a flow that would make you niddah.

It is generally advisable to abstain from marital relations from the onset of staining until it becomes clear either that a flow is beginning or that the staining has ended. This is a voluntary precaution against a flow beginning during relations; it is not a halachic requirement. Learn more here, under "Conduct while Staining."

Keep in mind that any stain on a white surface susceptible to tumah (e.g., a sheet or towel) cannot be ignored and must, at least, be evaluated as a ketem (stain). But if you leaked through your pajamas and onto your bed, it is likely that you have a flow. In that case, the leniencies of stains (such as colored surfaces) do not apply, and you would be in niddah.

Please see our article here for an in-depth discussion of the laws of stains, and our video here for a helpful presentation of the distinction between a stain and a flow.

Please feel free to get back to us with any further questions.

This response was updated on 22 June, 2025.