【Disease】 , 【disorder】 , 【condition】 , 【affection】 , 【ailment】 ,  【malady】 , 【complaint】 , 【distemper】 , 【syndrome】 denote a deranged bodily state usually associated with or amounting to a loss of health.

【Disease】 in its usual and broadest use implies an impairment of the normal state of the living body or of one or more of its parts marked by disturbance of vital functions and usually traceable to a specific cause (as a parasite, a toxin, or a dietary deficiency).

As used in names of specific abnormal states, 【disease】 implies the existence of a regularly occurring identifying group of symptoms and, often, of a known cause.

【Disorder】  is commonly interchangeable with 【disease】 , but typically it stresses the disordered state without regard to cause.

【Disease】 may sometimes be used more narrowly to distinguish an abnormal state resulting from an infective process and is then distinguished from or subordinated to 【disorder】 .

【Condition】 and the less common 【affection】 both imply a particular and usually an abnormal state of the body or more often of one of its parts; neither suggests anything about the cause or severity of such state.

【Ailment】 , 【malady】 , and 【complaint】 are used chiefly of human disorders, and all imply a degree of indefiniteness.

【Ailment】 often suggests a trivial or chronic 【disorder】 .

【Malady】 , on the other hand, usually stresses the mysterious or serious character of a 【disorder】 .

【Complaint】 carries no inherent implication about the seriousness of the 【disorder】 but in stressing the invalid’s point of view may suggest the distress that accompanies ill health.

【Distemper】 , which formerly applied to human disorders, is now used almost entirely of diseases of lower animals and more particularly to denote specifically certain severe infectious diseases (as a destructive virus 【disease】 of the dog and related animals, strangles of the horse, or panleucopenia of the cat).

【Syndrome】 is often used interchangeably with  【disease】 to denote a particular 【disorder】 , but in precise professional thinking such interchangeability does not imply strict synonymy, since 【syndrome】 denotes the group or pattern of signs and symptoms that constitute the evidence of 【disease】 and carries no implication about causation; thus, one might use either Ménière’s 【disease】 or Ménière’s 【syndrome】 to denote a particular 【disorder】 centered in the inner ear; however, one would say that the  【syndrome】 (not 【disease】 ) of recurrent dizziness, ringing in the ears, and deafness suggests the presence of Ménière’s  【disease】 .

Certain of these terms also are comparable in other uses and especially as applied to mental, spiritual, or emotional abnormal states.

【Disease】 usually connotes evident derangement requiring remedies or a cure.

【Ailment】  implies something wrong that makes for unsoundness, weakness, or loss of well-being.

【Malady】 , especially as contrasted with 【disease】 , implies a deep-seated morbid 【condition】 or unwholesome abnormality.

【Distemper】  usually harks back to its earlier reference to human ailments and stresses a lack of balance or of a sense of proportion.

【Syndrome】  retains its implication of a group of contributory signs and symptoms.