Vaginal bleeding can be a symptom of menstruation or be caused by a number of diseases, hormonal changes or pregnancy. Symptoms of vaginal bleeding can often be treated with medications such as birth control pills. Vaginal bleeding is any bleeding from the vagina. It can refer to bleeding associated with menstruation or bleeding that is not associated with menstruation, such as from trauma or a medical condition. In most cases, vaginal bleeding refers to bleeding that is not related to menstruation. Bleeding between periods or bleeding outside of your normal menstrual cycle is abnormal vaginal bleeding. This type of bleeding can be random, impossible to predict, and may be accompanied by pain or other symptoms. Vaginal bleeding that is not caused by menstruation can be caused by many factors such as: Health or medical conditions; Medicines; Pregnancy; Hormonal imbalance; Menopause; Injury or trauma; Infection. Abnormal vaginal bleeding can occur at any age. After menarche (the first menstrual period), menstrual cycles may not always occur on a regular schedule. The same goes for the years leading up to menopause. During perimenopause, the number of days between periods may change, be missed altogether, or bleeding may be unusually heavy or light. There are many causes of vaginal bleeding other than menstruation. Some of the more common causes are medical conditions, hormonal disorders, and pregnancy complications. Medical conditions Cancer of the female reproductive system. This can include cancer of the cervix, endometrium (lining of the uterus), ovaries or fallopian tubes. Blood coagulation disorders. A problem with normal blood clotting may be the result of an inherited condition such as haemophilia or von Willebrand disease, a low red blood cell count (thrombocytopenia), a deficiency of vitamin K (which helps the body produce clotting factors) or as a side effect from taking certain medicines (such as blood thinners). Hypothyroidism. An underactive thyroid gland can disrupt the normal menstrual cycle. Uterine fibroids. These are benign formations that develop from the muscle tissue of the uterus. Their size, number, growth rate and location in the uterus can vary greatly. Adenomyosis. A condition in which the lining of the uterus grows through the wall of the uterus. Uterine (endometrial) polyps. An overgrowth of cells on the lining of the uterus. Polyps are usually not cancerous, but some can develop into precancerous polyps. Severe cervicitis. Cervicitis is an inflammation or infection of the cervix. Endometrial hyperplasia. The endometrium becomes too thick, usually due to a hormonal imbalance of estrogen and progesterone. This condition is not cancerous, but in some cases it can lead to uterine cancer.Hormonal imbalance Anovulation. Disorders in the process of egg maturation can be caused by a disorder of the ovaries themselves or by a problem in the way the brain signals to the glands that control ovulation. Hormonal birth control pills. Some women report breakthrough bleeding while taking oral contraceptives. The problem tends to resolve itself. Polycystic ovary syndrome. It is a type of hormonal imbalance that causes irregular periods, weight gain, acne and male pattern baldness. Pregnancy complications Ectopic pregnancy; Detachment of the placenta; Placenta previa; Premature birth; Abortion. References: 1. Academy of Family Physicians. Abnormal Uterine Bleeding (https://familydoctor.org/condition/abnormal-uterine-bleeding/). 2. American College of Obstetricians and Gynecologists. Abnormal Uterine Bleeding (https://www.acog.org/womens-health/faqs/abnormal-uterine-bleeding). 3. American Pregnancy Association. Bleeding During Pregnancy (https://americanpregnancy.org/healthy-pregnancy/pregnancy-complications/bleeding-during-pregnancy/). 4. Jeanmonod R, Skelly CL, Agresti D. Vaginal Bleeding (https://www.ncbi.nlm.nih.gov/books/NBK470230/). 2021 Jul 21. In: StatPearls [Internet]. Treasure Island, FL: StatPearls Publishing;