the.com/lump in throat

means The tight, swelling sensation in the throat that comes with suppressed emotion, usually grief, nostalgia, or tenderness, right before (or instead of) tears.

from Not a borrowed or coined word so much as an anatomical fact turned into idiom — the feeling really is caused by the throat's muscles tensing and the glottis tightening when you fight back tears, a reflex tied to the autonomic nervous system. English speakers have described this sensation as a 'lump' since at least the 1800s, the word 'lump' itself coming from Middle English/Scandinavian roots meaning a shapeless mass — apt, since the feeling is exactly that: something thick and nameless lodged in the throat with nowhere to go.