nothing really causes poor hygiene per se. it is a choice unfortunately. your nephew can easily change but chooses not to. you could have a heart-to-heart talk to him again but a decision to improve his hygiene habits may still be ignored. if he had a significant other they may have the influence but as an aunt you can only do so much. like any bad habits his lack of personal hygiene may be difficult to change. unless he decides to do it.
what could be the cause(s) of very bad hygene habits? . my nephew age25 has very bad hygene habits like not knowung that he needs to bathe on a regular basis. he also doesn't get that he should wash his hands after visiting the bathroom. it's so bad that he has to be told to shower at which pont he will. i noticed his tendency to "smell" at an early age and i spoke to him about it and reaffirmed how important it is to maintain good hygene. i concluded he would grow out of it but years later he's older and much worse. please help. . . . thanks