Irregular periods are characterized by variations in the time between each of your periods, the number of days that your periods last and abnormal blood loss (whether less or more than usual) during a period.
A number of factors can cause this problem, such as eating disorders, significant weight loss or gain, anaemia, menopause, thyroid disorders, hormonal imbalance, liver disease, tuberculosis, irritable bowel syndrome, diabetes, recent birth or miscarriage, polycystic ovarian syndrome, uterine abnormalities and other health conditions.