A medical sign is an objective indication of some medical fact or characteristic that may be detected and still or video photographed or audio-recorded by a patient or anyone, especially a physician, before or during a physical examination of a patient. For example, whereas a tingling paresthesia is a symptom (only the person experiencing it can directly observe their own tingling feeling), erythema is a sign (anyone can confirm that the skin is redder than usual). Symptoms and signs are often nonspecific, but often combinations of them are at least suggestive of certain diagnoses, helping to narrow down what may be wrong. In other cases they are specific even to the point of being pathognomonic. Some signs may have no meaning to the patient, and may even go unnoticed, but may be meaningful and significant to the healthcare provider in assisting diagnosis.