What with

"What with the cold weather and my bad leg, I haven’t been out for weeks."

What is the meaning and origin of the expression "What with"?

It is a construction in use in English since the Middle Ages: it means "in consequence of, on account of, as a result of; in view of, considering (one thing and another)". Centuries ago English people also said "What through..." and "What for..." which meant the same thing; but these expressions are now obsolete. (VSD)