Chelsea striker Fran Kirby has revealed she has been suffering with an illness which has kept her out for three months.

The 26 year-old has not featured for the Blues since their 1-0 victory over Manchester United in November.

And now Kirby has spoken about the condition she has - called pericarditis - which relates to the inflammation of the fluid-filled sac around her heart.

She said: "I am feeling 100 times better compared to when this started. I was struggling with understanding how it happened and why it happened as I was feeling good with no injuries and enjoying training with the team, so it was frustrating at the time.

"When I became ill the frustration went away as I didn’t even have the energy to be frustrated, I had no emotion as I was too tired. It took over my life in a negative way, I couldn’t even get up to make food.

"Now that I am feeling more like a human being I can smile again and be in a room with people again. Before, when people were having conversations with me I couldn’t acknowledge them. I was just sitting there thinking ‘I am so ill, I am so ill’, it was just constantly on my mind."

Symptoms of the condition include sudden onset of sharp chest pain, fever, nausea, shortness of breath and weakness.

But while it has hampered the England forward for a number of months, Kirby is confident she will return to the pitch soon.

"Now I am coming to the other end of it, I am back around the girls more, I have the energy to come in or go to the pool when they are doing recovery," she added.

"I want to be back on the pitch more than anyone! I also know it will take time and I am not going to heal overnight and it is a day-by-day process.

"I know how ill I was and I don’t want to go back to that, I want to make sure when I come back I am 100 per cent with no symptoms and I am ready to go."

Meanwhile, Chelsea boss Emma Hayes has stuck firmly behind Kirby as she continues her road back to full fitness.

"Fran is a massively important part of our squad and she knows that, but while winning football matches is important, it is not more important than her health," she said.

"Good health is the priority in our culture, and her good health matters above and beyond anything else.

"Our job, when she is ready, is to make sure she comes back at even higher level than before.

"I can also assure the fans they will see a lot more of Fran Kirby playing and scoring goals for Chelsea."

Chelsea face Liverpool tonight at 7pm in the fifth round of the FA Cup.