Biological factors play a major role in the development of mental illness. 生物因素在精神疾病的發展過程中起著很重要作用。
Sciatic pain is induced by mechanical or biological factors either by direct stimulation of axons or by neuroischemia. 機械因素或生物因素可誘發坐骨神經痛,既可以通過直接刺激神經軸突也可由於神經缺血所誘導。