Fig.: to put in arduous labor

Her family was so proud of her when Lisa received honors at graduation because they knew she had put a lot of sweat, blood and tears all into her studies

Quando Lisa si è laureata con lode, la sua famiglia era molto orgogliosa perché sapeva che ogni esame le era costato sudore lacrime e sangue

On May 13, 1940, Winston Churchill, recently appointed Prime Minister, addressed the House of Commons with these words:
"I say to the House... I have nothing to offer but blood, toil, tears and sweat"
However similar lines can be found in John Donne's "An Anatomie of the World (1611):
That'tis in vaine to dew, or mollifie
It with thy teares, or sweat, or blood:...
or in Byron's "The Age of Bronze":
Year after year they voted cent. by cent.,
Blood, sweat, and tear – wrung millions – why? for rent!