《黄帝内经·素问·疏五过论》
医生诊察这种病，病的初期，由于病不在脏腑，形体也无改变，医生常诊而疑之，不知是什么病。
医工诊之，不在藏府，不变躯形，诊之而疑，不知病名。
Doctors examining this illness, in the early stage, due to the illness not being in the internal organs, the physical form also does not change, the doctors often examine it with doubt, not knowing what the illness is.