Muaj ntau ntau yam ua rau mob plab hnyuv, thiab feem ntau yog cov neeg mob uas muaj ntau yam qog nqaij hlav, tshwj xeeb tshaj yog cov qog nqaij hlav plab. Raws li kev txheeb cais tsis tiav, kwv yees li 30% ntawm cov neeg mob qog noj ntshav yuav muaj kev cuam tshuam ntau yam, uas ncaj qha ua rau cov neeg mob tsis muaj peev xwm noj tau ib txwm, nrog rau mob plab, tsam plab, thiab mob hnyav, plab hnyuv perforation, thiab txawm tias. tej yam kev phom sij.