Information　needs　motivate　human　information　behavior.　Knowledge　of　information　needs　is　critical　for　user-centered　information　behavior　research　and　system　design.　In　consumer　health　information　behavior　research,　there　is　a　lack　of　understanding　of　how　consumer　health　information　needs　(CHIN)　is　measured　in　empirical　studies.　This　study　is　a　systematic　review　of　empirical　quantitative　studies　on　CHIN,　with　a　focus　on　how　CHIN　is　defined　and　operationalized.　A　search　of　six　academic　databases　and　citation-track　of　relevant　articles　identified　a　total　of　216　relevant　articles.　These　articles　were　analyzed　using　the　qualitative　content　analysis　method.　We　found　that　few　included　articles　explicitly　defined　either　CHIN　or　information　needs　in　general.　When　definitions　were　given,　they　were　from　a　cognitive　perspective　and　largely　ignored　the　multidimensionality　of　the　concept.　Consistent　with　this　cognitive-centered　conceptualization,　CHIN　was　operationalized　primarily　as　information　topics,　with　some　articles　also　measuring　several　additional　attributes,　including　level　of　importance,　fulfilment,　amount　of　information　needed,　and　frequency　of　needs.　These　findings　suggest　that　CHIN　is　undertheorized.　To　address　this　gap,　future　studies　should　attend　to　social　and　emotional　dimensions　of　CHIN,　such　as　motivations,　goals,　activities,　and　emotions.　Further,　more　research　is　needed　to　understand　how　CHIN　is　related　to　consumer　health　information　seeking　behavior　and　to　the　social　and　environmental　context　in　which　the　needs　arise.