lose sleep over

To worry excessively about someone or something, perhaps to the point of literally being unable to sleep. Oh, those two argue all the time—it's nothing to lose sleep over. I hope you won't lose sleep over this issue with the printer. I'll call IT in the morning and see if they can fix it.

To worry excessively about someone or something, perhaps to the point of literally being unable to sleep. I hope you won't lose sleep over this issue with the printer. I'll call IT in the morning and see if they can fix it. I'm trying not to lose sleep over my daughter, but I just worry about how she'll cope with the pressures of high school.

Fig. to worry about someone or something a lot, sometimes when one should be sleeping. (Often used with any and the negative.) Yes, Kelly is in a little bit of trouble, but I'm not going to lose any sleep over her. Don't lose any sleep over the matter. I refuse to lose sleep about it.

Worry about, as in It's too bad the experiment failed, but I'm not going to lose sleep over it. This expression, often put negatively, alludes to actual insomnia caused by anxiety. [First half of 1900s]

To worry about. This expression, often used negatively—that is, something not to lose sleep over, dates from the mid-twentieth century. The novelist Norman Mailer used it in Advertisements for Myself (1959), “It’s not the sort of thing I lose sleep over.”