- ailment: an illness that is not very serious: ốm nhẹ
- illness: the state of being physically or mentally ill (sự đau ốm ); a type or period of illness (căn bệnh, thời gian bị bệnh)
- disease: an illness affecting humans, animals or plants, often caused by infection (bệnh dịch) ; something that is very wrong with people’s attitudes, way of life or with society (tệ nạn xã hội)