If leukorrhea is thin like water and has an odor, the following causes are common in clinical practice: 1. bacterial vaginosis, which will have a great fishy odor and can be treated clinically with metronidazole. 2. cervical cancer in advanced stage will have more vaginal discharge with foul odor. 3. once endometrial cancer is co-infected, the vaginal discharge will be like plasma and have a great odor. It is recommended to do routine white belt examination, cervical cancer screening and ultrasound to understand whether there are abnormal echoes in the endometrium. If necessary, diagnostic scraping can be done and pathological tests can be sent, and corresponding treatment will be given according to the results.