<http://webisa.webdatacommons.org/183029117>	<http://www.w3.org/ns/prov#value>	"But in a small percentage of cases, these headaches can be due to a serious underlying condition, such as a hemorrhage, brain aneurysm, stroke, cervical artery dissection or subdural hematoma." .
<http://webisa.webdatacommons.org/prov/193218308>	<http://www.w3.org/ns/prov#wasDerivedFrom>	<http://webisa.webdatacommons.org/183029117> .
<http://webisa.webdatacommons.org/183029117>	<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>	<http://www.w3.org/ns/prov#Entity> .
<http://webisa.webdatacommons.org/183029117>	<http://www.w3.org/ns/prov#wasQuotedFrom>	<medicalxpress.com> .