Gender isn’t always as clear-cut as black and white. Shades of gray exist among men and women who don’t quite fit into a single gender. A 44-year-old married Chinese man found out he too wasn’t exactly all male when bouts of stomach pain and blood in his urine sent him to the doctor for an unexpected diagnosis. The Chinese man, identified by his surname Chen, discovered he was actually a female experiencing menstrual cramps, after a CT scan revealed he had a uterus and ovaries.

"He was wearing men’s clothes and had short hair so we didn’t think that he would be a female at the beginning," said the Chief of the First People’s Hospital of Yongkang, according to Shanghaiist.com. The doctors proceeded to treat Chen like a male patient, until the CT scan and a chromosome examination showed he not only had female genitalia, but a pair of XX sex chromosomes, suggesting Chen was genetically female. He learned his feelings of constant fatigue, accompanied by a swollen face and legs were all due to him being on his period throughout his life.

Although doctors have not confirmed whether Chen is a hermaphrodite or intersex, he does have two types of genitalia — a penis and a uterus with ovaries. Typically, people who are intersex do not have a reproductive or sexual anatomy that fits the definitions of female or male, says the Intersex Society of North America (ISNA). However, there are cases of people who are born with genitals that seem to be in-between the usual male and female types, such as a boy being born with a notably small penis, or with a scrotum that is divided so that it has formed more like a labia.

Chen claims he has enjoyed an active sex life with his wife of 10 years, but doctors doubt this since his genitals are different from other men, and he did not possess an Adam’s apple. People who are intersex sometimes don’t find out they have intersex anatomy until they reach the age of puberty, find themselves an infertile adult, or die of old age, and are then autopsied. According to the ISNA, people live and die with intersex anatomy without anyone (including themselves) ever knowing.

Not only was Chen diagnosed as a female after 44 years, but doctors also found the married man suffered from the genetic disorder — congenital adrenal hyperplasia — where the adrenal glands produce more or less of the hormones that shape the development of genitals and secondary sex characteristics such as body hair. Doctors found it unusual Chen possessed little facial hair.

Since Chen has lived his entire life without adequate hormone treatment for his genetic disorder, his adrenal glands developed benign tumors and were removed, the Daily Mail reported. Furthermore, genetic testing conducted by doctors at First People’s Hospital of Yongkang confirmed Chen is a woman, biologically. It is not known whether the man wants to change his gender identity.

Chen’s case isn’t the only one seen in China. Last year, an unidentified 66-year-old man learned his abdominal pain was due to an ovarian cyst, revealing he is genetically a woman. The patient was found to have a rare combination of Turner syndrome and congenital adrenal hyperplastia, which has interfered with the development of reproductive organs and secondary sex characteristics, the South China Morning Post reported.