Cov chav ua haujlwm yuav tsum tau muab faib ua nruj me ntsis rau hauv cov chaw txwv (cov chav ua haujlwm tsis muaj menyuam), ib nrab- thaj chaw txwv (cov chav ua haujlwm tsis muaj paug), thiab thaj chaw tsis txwv. Muaj ob txoj hauv kev rau kev cais peb thaj chaw no: ib qho yog tso qhov txwv thiab ib nrab- txwv thaj chaw ntawm cov plag tsev sib txawv, uas tso cai rau kev sib cais ntawm kev nyiam huv tab sis yuav tsum muaj ob txheej txheej, nce cov neeg ua haujlwm, thiab tsis yooj yim rau kev tswj hwm; lwm qhov yog kom muaj kev txwv thiab tsis txwv thaj chaw nyob rau hauv ntau seem ntawm tib pem teb, nrog rau ib nrab- txwv tsis pub thaj chaw nyob nruab nrab, sib koom cov khoom siv. Qhov kev tsim no yooj yim dua rau kev tswj hwm.
Cov chaw txwv muaj xws li chav ua haujlwm tsis muaj menyuam, chav dej, chav tsis muaj menyuam, thiab chav cia tshuaj. Semi-cov chaw txwv muaj xws li chav kho mob xwm txheej ceev lossis cov chaw ua haujlwm tsis huv, chav ntsuas ntsuas thiab hnav khaub ncaws, chav npaj tshuaj loog, thiab chav ua kom tsis muaj menyuam. Cov chaw tsis muaj kev txwv muaj xws li chav hloov pauv, chav plaster, chav kuaj, chav pov tseg pov tseg, chav tshuaj loog rov qab, chav saib xyuas neeg mob, chav so cov neeg ua haujlwm, chav noj mov, thiab chav so rau cov neeg mob phais tsev neeg. Chav ua haujlwm thiab cov chaw saib xyuas neeg mob yuav tsum nyob ze ntawm qhov nkag.