苦悶[kumon] anguish
煩悶[hanmon] worry
悶える[modaeru] to be in agony
悶死[monshi] die in agony
悶着[monchaku] trouble

憂悶[yuumon] anguish
悶悶[monmon] worrying endlessly
遣悶[kenmon] driving away melancholy
身悶え[mimodae] writhing (in agony)
悶絶[monzetsu] fainting in agony