Answered by Regina from Poland | May. 23, 2016 20:36
Faeez, both of you can apply for an S2 type to go to PRC for the medical checkup. The documents for S2 type include the passport and copies of all the used pages, the completed application form affixed with a passport-style photo, an invitation letter from a Chinese hospital, an introduction letter from the ministry of foreign affairs of Nigeria, and your bank savings account.
Afterwards, prepare two sets of applications and go to the embassy of PRC between 15:00 and 17:00 every Tuesday or Thursday to submit the applications and make an appointment for the interview.