Menstrual irregularity: This is the most common cause of vaginal bleeding, especially in women of reproductive age, due to hormonal changes or irregular ovulation.

Pregnancy-related complications (e.g., miscarriage, ectopic pregnancy): These conditions can cause vaginal bleeding due to implantation issues or complications with the pregnancy.
Infections (e.g., pelvic inflammatory disease, cervicitis): Infections can lead to inflammation and bleeding in the reproductive tract.
Hormonal imbalances (e.g., polycystic ovary syndrome, thyroid disorders): Hormonal changes can disrupt the normal menstrual cycle, leading to irregular bleeding.
Contraceptive-related bleeding: Certain contraceptives, such as intrauterine devices (IUDs) or hormonal birth control, can cause irregular bleeding.

Ectopic pregnancy: Although not the most common cause, ectopic pregnancy is a life-threatening condition that requires immediate attention.
Malignancy (e.g., cervical, uterine, or ovarian cancer): Cancer can cause abnormal vaginal bleeding, and early detection is crucial for effective treatment.
Placenta previa or placental abruption: These pregnancy complications can cause severe bleeding and require prompt medical attention.
Uterine rupture or perforation: Although rare, these conditions can be life-threatening and require immediate surgical intervention.

Uterine arteriovenous malformation: A rare vascular anomaly that can cause abnormal bleeding.
Von Willebrand disease or other bleeding disorders: These conditions can increase the risk of heavy or prolonged menstrual bleeding.
Foreign body or trauma: Rarely, a foreign object or trauma to the reproductive tract can cause vaginal bleeding.
Endometrial hyperplasia or polyps: Although not typically life-threatening, these conditions can cause abnormal bleeding and may increase the risk of malignancy.