### Menstrual-Related Causes
1. **Menstruation**: Regular monthly bleeding as part of the menstrual cycle.
2. **Ovulation**: Some women experience spotting during ovulation.
3. **Menstrual Irregularities**: Including anovulation (lack of ovulation), oligomenorrhea (infrequent periods), and polymenorrhea (frequent periods).
### Pregnancy-Related Causes
1. **Implantation Bleeding**: Light bleeding or spotting when the fertilized egg attaches to the uterine lining.
2. **Miscarriage**: Bleeding can be a sign of miscarriage, especially in early pregnancy.
3. **Ectopic Pregnancy**: A potentially life-threatening condition where the embryo implants outside the uterus.
4. **Placental Issues**: Such as placenta previa (placenta covers the cervix) or placental abruption (placenta detaches from the uterine wall).
### Hormonal Causes
1. **Hormonal Contraceptives**: Birth control pills, patches, or injections can cause breakthrough bleeding.
2. **Hormonal Imbalances**: Conditions like polycystic ovary syndrome (PCOS) or thyroid disorders can lead to irregular bleeding.
3. **Perimenopause and Menopause**: Hormonal changes can cause irregular bleeding patterns.
### Structural Causes
1. **Fibroids**: Non-cancerous growths in the uterus.
2. **Polyps**: Growths on the cervix or inside the uterine lining.
3. **Endometriosis**: Tissue similar to the uterine lining grows outside the uterus.
4. **Adenomyosis**: Uterine lining tissue grows into the muscular wall of the uterus.
### Infections and Inflammation
1. **Infections**: Such as sexually transmitted infections (STIs) or pelvic inflammatory disease (PID).
2. **Cervicitis**: Inflammation of the cervix.
3. **Vaginitis**: Inflammation or infection of the vagina.
### Cancer
1. **Cervical Cancer**: Can cause irregular bleeding, especially after intercourse.
2. **Uterine (Endometrial) Cancer**: Can cause abnormal bleeding.
3. **Vaginal or Vulvar Cancer**: Rare but can also lead to bleeding.
### Other Causes
1. **Trauma**: Injury to the vaginal area.
2. **Medications**: Blood thinners and other medications can cause bleeding.
3. **Medical Procedures**: Such as a Pap smear, biopsy, or surgery.