To bring ruin on oneself; to cause one's own harm by one's actions or decisions (i.e., to dig one's own grave).
借金を返さずにまた新しいローンを組むなんて、結局自分の首を絞めるだけだ。
Taking out another loan without repaying debts will only dig your own grave in the end.
会社の決定が従業員を追い詰め、長期的には自分の首を絞めることになった。
The company's decision pressured employees and in the long run ended up harming the company itself.
そんな無理な約束をすると、あとで自分の首を絞めることになるよ。
If you make such an unreasonable promise, you'll be the one suffering later.