At death’s door
Definition 1 of 1
Pro Tip 1/3Figurative Use
The phrase is not always literal, can imply someone is extremely weak or exhausted. 
After running the marathon, he felt like he was at death's door.
Pro Tip 2/3Emotional Weight
The phrase carries heavy emotional connotations, use with sensitivity to others' feelings. 
I avoided saying she was at death's door to not upset her family.
Pro Tip 3/3Dramatic Flair
It can be used dramatically to emphasize dire situations, not just concerning health. 
After the company's huge loss, it was at death's door financially.