About: http://webisa.webdatacommons.org/455663187

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	To complicate matters, pain is a subjective symptom, and headache diagnosis is based on clinical features and cannot be objectively measured by a blood test or identi???ed by an X-ray.
http://www.w3.org/ns/prov#wasQuotedFrom	dana.org