Chronic pain is difficult to treat; even the most effective medications provide only modest relief to a minority of patients. This can be explained partly by pain’s subjective nature, and partly by the fact that its source can be difficult to pinpoint.
慢性疼痛很难治愈；即便是效力最强的药物也只能略微减轻少数病人的疼痛。这部分是因为疼痛的主观性质，部分是因为疼痛根源难以精确查明的事实。