When one's menstrual period is heavy in flow. This can be perfectly fine and safe, or it can be a symptom or side effect. For some, it is a side effect of medication, for others it may just be genetic.

Some folks that deal with heavy periods prefer to wear adult diapers or reusable menstrual underwear, especially while they sleep, to avoid leaking.

If you are soaking a heavy-duty menstrual pad in an hour, becoming shaky, or it is worrying you for any other reason, talk with a doctor.