[mass noun]abnormal anxiety about one's health, especially with an unwarranted fear that one has a serious disease 疑病(症)
语源
late Middle English(in the Greek sense): via late Latin from Greek hupokhondria, denoting the soft body area below the ribs, from hupo 'under' + khondros 'sternal cartilage'. Melancholy was originally thought to arise from the liver, gall bladder, spleen, etc