The British nurse who almost died after contracting Ebola while volunteering in Sierra Leone has been discharged from hospital after making a full recovery.

Pauline Cafferkey said she was “happy to be alive” as she thanked staff at the Royal Free Hospital in London who she said saved her life.

Doctors had described her condition as “critical” during the three weeks she received treatment for the deadly virus and her family and friends were preparing for the worst. Cafferkey admited that then she had felt like “giving up”, but was now looking forward to returning to “normal life” and had no plans to go back to Africa.

The 39-year-old nurse was diagnosed with Ebola after returning to Glasgow last month and was admitted to the city’s Gartnavel hospital on December 29 before being transferred the next day to the Royal Free. She had been working with Save the Children at the Ebola treatment centre in Kerry Town before returning to the UK.

She told the BBC: “I am just happy to be alive. I still don’t feel 100% – I feel quite weak – but I’m looking forward to going home. I want to say a big thank you to the staff who treated me – they were amazing. They were always very reassuring and I knew I was in the best hands. They saved my life.”

Cafferkey said that when first admitted to hospital, she had not felt unwell. “I just couldn’t understand all the fuss,” she said, but that she felt frightened as her health deteriorated. “Obviously at the back of my mind I had seen what could happen and what could potentially happen to me. There was a point, which I remember clearly. I do remember saying, ‘That’s it, I’ve had enough.’”

Cafferkey, from Cambuslang, South Lanarkshire, said she was grateful to the Royal Free Charity for lending her an iPad to use while she was in the hospital’s high-level isolation unit. She said: “As I was beginning to recover, I listened to lots of music and that was a massive help. I also had lots of Irn-Bru to help me through!”

Cafferkey said she planned to have a break from aid work. “I just want to go back to my normal job, my normal life, and I think my family will be happy with that as well.”

While at the hospital, she was under the care of the infectious diseases team, led by Dr Michael Jacobs. He said: “We are delighted that Pauline has recovered and is now well enough to go home. I am very proud of the staff who have been caring for her. It is because of the skill and hard work of the entire team that she is now able to go home.”

Health secretary Jeremy Hunt said: “I am delighted that Pauline Cafferkey has been discharged from hospital and can now return home. Her selflessness and courage are remarkable and she represents the very best of NHS values. I would like to thank all the staff at the Royal Free who have worked tirelessly to provide her with world class care and treatment.”

Professor Dame Sally Davies, chief medical officer for England, also welcomed the news: “It is wonderful to hear that Pauline Cafferkey has recovered. This is testament to the hard work and dedication of the team at the Royal Free, who have worked around the clock to help bring about this happy outcome.”

As a result of Miss Cafferkey being allowed to transfer flights from London to Scotland, shortly before she developed symptoms for the disease, Professor Davies ordered a review of procedures at airports handling passengers arriving from Ebola infected countries.

International Development Secretary Justine Greening said she was “absolutely delighted” by the news. “All of our thoughts have been with her and her family during her recovery and this is fantastic news. Pauline and all of the NHS volunteers helping to contain, control and defeat Ebola are making a huge difference in the fight against this horrible disease. Their hard work is saving lives and they have the thanks of the UK and Sierra Leone alike. My thanks also to the staff at the Royal Free for all their help in getting Pauline well.”

Save the Children has launched an investigation into how Cafferkey was infected, but admits it may never establish the exact circumstances. The charity’s chief executive, Justin Forsyth, said: “We are delighted for Pauline Cafferkey and her family that she has fully recovered from Ebola. Pauline is a dedicated humanitarian who worked tirelessly and selflessly in the fight against Ebola.

“Despite the risks to her own safety, she volunteered to use her nursing skills to help save lives and treat those in dire need in Sierra Leone. The bravery of Pauline and everyone who has worked to defeat Ebola makes us even more determined to redouble our efforts to beat the disease.”