沥血叩心 (瀝血叩心) lì xuè kòu xīn

lì xuè kòu xīn set phrase to drip blood and spit out your heart; work your heart out
Domain: Idiom 成语
Notes: Variant of 呕心沥血 (CC-CEDICT '瀝血叩心'; Guoyu '瀝血叩心')