I try not to defend my Big Blind just because I’ve already invested the blind.
When I'm short, every chip becomes more valuable, so I look at the effective stack, position, raise size, and opponent's range before defending.
With around 10–15BB, I'm often more inclined to look for a good reshove spot rather than call and play a difficult postflop hand.
I definitely don't want to bleed away chips with marginal hands just because the price looks cheap.
Sometimes folding the Big Blind feels painful, but protecting your remaining stack and preserving fold equity is more important than defending every blind.