Jessie J has revealed that her hair is falling out "like crazy" following her breast cancer surgery.

The British singer underwent a mastectomy in June, the same month that she publicly announced her early-stage breast cancer diagnosis.

On Tuesday, Jessie took to Instagram to share a clip filmed two weeks ago, in which she opened up about the effects of the surgery.

"My hair has been falling out like crazy since the surgery," the 37-year-old said. "Five weeks today since my surgery, and I'm feeling okay."

"I've still got quite a lot of cording so that's my main focus," she added, referring to axillary web syndrome (AWS), a condition where tight cord-like structures develop under the skin, typically in the inner arm, following breast cancer surgery.

The Price Tag hitmaker also said that her breasts are uneven and still sore.

Jessie, who shares a two-year-old son named Sky with her boyfriend, Chanan Colman, then went on to say that she has had to learn to prioritise as she continues to recover from the surgery.

"I'm just trying to figure out what the next six months will look like," she told viewers. "I know I can't do everything that I was supposed to be doing but I just want to be able to make it work the best I can for everybody. Me, Sky, my fans, but in the right order."

She added, "You are always gonna leave some people disappointed. My perspective on everything has changed so much."

Jessie's update comes just days after she revealed that she would have to undergo further surgery, having recently been hospitalised with an infection and a "little fluid" on her lungs.