The 32-year-old singer was diagnosed with Ménière's syndrome and struggled to walk in a straight line.
Speaking on an Instagram live, she explained: "I woke up and felt like I was completely deaf in my right ear, couldn't walk in a straight line.
"Basically I got told I had Ménière's syndrome. I know that a lot of people suffer from it and I've actually had a lot of people reach out to me and give me great advice, so I've just been laying low in silence.
"Now's the first time I've been able to sing and bear it. I just miss singing so much and being around anyone."
She went on: "It could be way worse, it is what it is. I'm super-grateful for my health. It just threw me off.
"On Christmas Eve I was in the ear hospital going, 'What is going on?'.
"But I'm glad I went early and they worked out what it was real quick and I got put on the right medicine so I feel a lot better today.
"I haven't sung for so long and when I sing loud, it sounds like there's someone trying to run out of my ear."
This isn't the first time Jessie J has struggled with her health and has previously spoken about how she battled a heart condition when she was a child and even suffered a stroke at the age of 18.
In her autobiography, Nice To Meet You, she explains how she was diagnosed with an irregular heartbeat when she was seven.
She wrote: "I remember collapsing a lot and having seizures. I was a sickly, skinny girl who had a slight green tinge to her skin because of the drugs and who was always in and out of hospital.
"There would be times when I'd be acting normal and then I'd just collapse.
"It was only then that people would realise I wasn't well. I suppose I was good at covering it up and I know I'm very good at that now."Featured Image Credit: Instagram/@jessiej