Why is it so important to wear a bra after breast reduction surgery?

Thank you for your question. Wearing a bra after reduction surgery is important to support the weight of the breast and hold shape while healing happens. That being said, if you slept one night without wearing one, you will be fine. It is unlikely that this small mishap will cause significant problems. Best of luck!

Accidents happen. If you spent a single night without a bra on after breast reduction, it's unlikely to cause any significant problems. Support after surgery is important, but missing a night by mistake isn't something to worry about. Be sure not to make a habit of it and you should be in good shape. 

Plastic surgeons differ on post-op guidelines for the type bra and the length of time to wear it following breast surgery procedures.  Although my practice provides patients with a surgical bra, a sports bra is fine; I do not recommend wearing an underwire bra.  I recommend that my patients wear the bra for six weeks after breast reduction surgery.  Going without it for one night is no reason for concern.In addition to facilitating wound healing, the bra also minimizes swelling, pain, and the formation of a seroma, or hematoma.

Not to worry, you did not do any permanent harm. Wearing a sports bra after breast surgery just provides a bit of support, may control some swelling and pain, and helps hold any dressings in place. It is not essential to a perfectly good result.