Yellow vaginal discharge may be caused by vaginitis, uterine fibroids and cervical cancer. 1. Vaginitis: Infection of vagina by trichomonas, bacteria and other pathogens triggers vaginal inflammation, resulting in yellow vaginal discharge, foul smell and other undesirable symptoms. 2. Uterine fibroid: it is the most common benign tumor in female reproductive system, which is mainly caused by the abnormal proliferation of uterine smooth muscle cells, and it will lead to the symptoms of increased vaginal discharge and yellowish color. 3. Cervical cancer: female patients with cervical cancer will have bad symptoms such as increased vaginal discharge, yellow color and bad smell. When women have the symptom of yellow vaginal discharge, it is recommended to go to the hospital for examination and diagnosis in time and choose corresponding treatment under the guidance of doctors.