Symptom/ˈsɪmptəm/ Definition 1 of 2Pro Tip 1/3Health-Related Context Use 'symptom' for observable effects of diseases or disorders. Dry coughing is a symptom of that new virus going around. Pro Tip 2/3Severity Levels 'Symptom' is neutral; it doesn't indicate how severe a health issue is. Even a mild headache can be a symptom worth checking out. Pro Tip 3/3Not Always Illness Symptoms can show reactions to treatments, not just illness. Side effects can include additional symptoms such as dizziness.