The four phases of the menstrual cycle are menstruation, the follicular phase, ovulation and the luteal phase. Common menstrual problems include heavy or painful periods and premenstrual syndrome (PMS).
Menstruation phase lasts for 3-5 days whereas menstrual cycle is of 28-29 days in normal human females.
The length of the menstrual cycle varies from woman to woman, but the average is to have periods every 28 days. Regular cycles that are longer or shorter than this, from 21 to 40 days, are normal.