The address of Ya'an Hengbo is No. 79, Bifengxia Road, Yucheng District, Ya'an City, Sichuan Province. The reasons for lack of sperm are as follows:

1. Chromosomal abnormalities: This is the most common cause. When a patient develops Klinefelter syndrome, the testicular spermatogenic epithelium will atrophy, resulting in small testicles, and the patient will have azoospermia. ;

2. Long-term oral administration of cottonseed oil: Long-term oral administration of cottonseed oil in childhood can cause damage to the testicular seminiferous epithelium, atrophy of the testicular seminiferous epithelium, and the occurrence of azoospermia;

3. Lateral cryptorchidism: Since the testis is located in the abdominal cavity, the high local temperature will also cause the testicular spermatogenic epithelium to atrophy. By querying the address of Ya'an Hengbo on Baidu Map, we learned that Ya'an Hengbo Hospital·Ya'an Obstetrics and Gynecology Hospital, a specialized hospital, is located at No. 79 Bifengxia Road, Yucheng District, Ya'an City, Sichuan Province. It is a general hospital. Ya'an City is located at the intersection of Sichuan-Tibet and Sichuan-Yunnan Highways, 120 kilometers away from Chengdu. It is the transition zone between the Sichuan Basin and the Qinghai-Tibet Plateau, the transition zone between Han culture and ethnic culture, and the transition zone between modern central cities and primitive natural ecological areas. It is the gateway and must-pass city of the ancient Southern Silk Road.