In 2011, rumors of an AIDS-like disease were spreading in Mainland China, which captured the attention of the media of China and Hong Kong and spread across the internet.[3] The Disease Prevention and Control Bureau of China stated that no new virus was found and that yinzibing was a mental health problem.[4][5]
In 2013 an epidemiological study conducted by the Army Medical University in China found the following symptoms in patients claiming to have yinzibing: crepitus (crunching noise from the joints when moved), thick white tongue coating, muscle twitches (fasciculation), dry skin, burping, chronic sore throat and several others.[6] The study found that 33% of yinzibing patients have low CD4 cells (less than 500 CD4 cells per mm3). The study concluded that this disease could not be completely explained by a mental disorder.
A 2019 study suggested the symptoms were explainable as chronic fatigue syndrome,[7] an illness usually precipitated by a viral infection.