A symptom can be defined as a "departure from normal function or feeling" which is experienced by a patient. Symptoms normally indicate the presence of some disease or abnormality. However, symptoms are subjective. This means that they are something observed by the patient and maybe different for different people. They are not objective and measurable.
Sometimes a symptom is not even an indication of sickness. It may just be a sign. For example, swelling breasts and thickening of the waistline are simply signs of pregnancy.
Whatever be the symptoms, positive or negative, they should not be ignored as they surely indicate a deviance from your normal pattern of life. If they are serious, causing inconvenience and interfering with your normal life, you should consult a medical practitioner. Different diseases have different symptoms; at the same time, certain symptoms, like pain or a fever, could be common to many diseases.