A 44-year-old man visited a hospital in Yongkang, Zhejiang Province with stomach pains and blood in his urine only to discover he is really a woman and menstruating.

Doctors at the First People's Hospital of Yongkang were stunned after CT scans revealed the apparent man, surnamed Chen, possesses a uterus and ovaries, local media reported on Wednesday.

"He had short hair and was dressed in man's clothes. We did not realize he was a female at first," said a doctor surnamed Zhao.

Though doctors also removed the benign adrenal tumor causing him abdominal discomfort, a chromosome test confirmed Chen's gender and that the blood was from menstruation.

Doctors also noted that Chen had no Adam's apple, no facial hair and a deformed penis.

Chen's condition was the result of adrenogenital syndrome, a disorder that affects the normal development of genitals and other gender characteristics.

The syndrome can be treated with hormone supplements if detected early, doctors explain.

Chen told doctors he has been married to his wife for 10 years and has not had trouble performing sexually.

zjol.com.cn