Physically frail, either through bad habits, bad luck or genetics. Generally used to refer to an undefined, slightly mysterious condition.
"No one can smoke when she's in the room."
"Do tell. Not even vaping? or pot?"
"As if. And she's got a lot of allergies. Can't eat anything with cilantro, or cumin."
"Well, she was never quite well..."
Commoner among men than you think.
Lou Reed, most definitely.
David Bowie...say no more.
Iggy Pop. Indeterminate whether it's self-induced, inherent, or both.
Daryl Hall, undefined auto-immune in youth, Lyme tick disease, in old age. Unlike the first three, non-self-medicator.
Also found in people with CCR5-δ32..