Despite standing 1.7 meters tall, Xiao Tan, from Changsha in Hunan province, tries to maintain a weight of around 40 kilograms.

This is not because he has an eating disorder, but because he has a rare condition known as hemophilia, which means his blood doesn't possess the needed proteins for clotting.

While a small cut is not an issue for most people, for those with hemophilia it can be potentially life-threatening.

Tan, who wishes to only use his family name for privacy reasons, keeps his weight so low to limit the amount of medicine he requires, as his treatment is expensive despite being partially covered by insurance.

It is estimated that the prevalence of hemophilia in China is about 3.6 per 100,000 people.

Despite some misunderstanding among some members of the community, hemophilia is not contagious, and is usually the result of an inherited mutated gene.

The 25-year-old was diagnosed with the condition when he was 3 years old.

However, back then Tan's family, living in Chaling county at the time, didn't have the financial means or medical knowledge to get him injected with clotting factor — blood plasma involved in the clotting process.

Therefore, whenever there was internal bleeding, he could only lie in bed, suffering great pain and waiting for the bleeding to stop.

"I'm told the pain can be even worse than when women give birth. And if the bleeding is not stopped, it means severe pain for a long time," he said.

Upon being diagnosed with hemophilia, his father blamed his mother as the mutation for the condition is usually passed from mother to son through the X chromosome.

He would argue with her and even physically beat her. After a while, his father left the family.

Tan began taking traditional Chinese medicine for the disease at an early age.

Whenever there was severe pain, his mother would put a hot towel on his joints and massage him to alleviate the pain.

When he was 10 years old, he almost died from severe internal bleeding.

The local TV station and newspaper ran stories about his plight, and many people donated money to help him get treatment and clotting factor from a hospital in Changsha.

"I have used all kinds of medicine, borrowed some from fellow patients with the condition and even used clotting factor that was out of date," he said.

"When there is bleeding, any medicine can be lifesaving, and expired medicine or even those for clinical trials are better than no medicine."

Since then, he has had clotting factor replacement therapy to treat bleeding episodes. Since 2022, the replacement therapy has been given regularly at home to help prevent bleeding episodes.

Tan graduated from the Hunan University of Chinese Medicine with a degree in acupuncture and massage in 2022.

Medical insurance in Changsha covers up to 300,000 yuan ($41,468) annually for medical bills associated with hemophilia.

He said he chose to study medicine because he was inspired by his many experiences with doctors over the years. He started documenting his daily life on social media platform Douyin, the Chinese version of TikTok, without revealing his condition at first.