old wound; scar
Refers to a physical injury from the past that may have left a scar or still causes trouble.
My old wound aches when it gets cold.
A scar from an old wound remains on his arm.
painful memory; past misdeed; old skeleton in the closet
Metaphorical use for an unpleasant past experience, a regret, or a past wrongdoing that still affects someone emotionally or socially.
That story is like reopening an old wound for him.
The politician's past misdeed was brought up again during the election.
傷跡 specifically means 'scar' as a visible mark, while 古傷 emphasizes the past nature of the wound or its metaphorical extension.
トラウマ is a loanword for psychological trauma, often more clinical or intense than the metaphorical 古傷, which can be a milder painful memory.
Standard kanji spelling; high frequency in news and common usage.
Rarely used kanji form; 疵 is an uncommon character for 'wound'.
Rarely used kanji form; 創 is an uncommon character for 'wound'.
Compound of 古 (old) and 傷 (wound). The metaphorical sense developed naturally from the idea of an old injury that still causes pain.