For Covid-19 patients who respond successfully to intensive care treatment and are able to be discharged from hospital, the road to recovery can still be a lengthy one.

The latest report into patients admitted into critical care for coronavirus so far in England, Wales and Northern Ireland showed that of 2,249 patients for whom data was available, only 344 (15%) had been discharged alive. A similar number had died (346 patients), while the majority – the remaining 1,559 – were still in critical care.

As it is early days in the spread of the virus, the figures from the intensive care national audit and research centre (IANARC) do not paint a complete picture. Additionally, little is known about what the recovery process looks like, but what is clear is that it will take time, even after leaving hospital.

Faiz Ilyas, 24, from Clayton near Bradford, was discharged from Bradford Royal Infirmary last week after eight days, including five in the hospital’s intensive care unit (ICU). He was not on a ventilator (the most intensive treatment) but told the Guardian: “When I get up and go to the bathroom or go to the garden, especially when I have a shower, I get really breathless afterwards. The doctors gave me exercises to utilise the whole of my lungs. They didn’t give me any timeframe [for getting better].”

It is a general rule that the sicker you are, the longer it will take to recover. As such, Covid-19 patients who have been on a ventilator will face the toughest convalescence.

The first step for those patients will be for their doctors to decide they can be taken off sedation and they will then try to get them breathing through the machine themselves. Only when the patient is able to do this will the clinicians remove the breathing tube, enabling the patients to speak, which in some cases – depending on how long they have been intubated – will be the first time in a while.

The ICNARC figures show that of those who have required ventilation in the UK so far, only a third (127 out of 388) have survived.

Among all Covid-19 patients for whom a critical care outcome (either discharged alive or died) has been recorded, 68% of those aged 70 or over died, compared with 46% of those aged 50 to 69 and 24% of patients aged 16 to 49. Men were also more likely to die than women, 52.2% compared with 44.6%.

Additionally, of those who were obese, 57.6% died compared with 45.8% who were overweight and 43.6% who were not overweight. While the findings are not conclusive, these risk factors are confirmed by data from other countries.

Even after coming off the ventilator, the patient will still need assistance getting enough oxygen and this is likely to be through a mask or, possibly, a continuous positive airway pressure ventilator (Cpap), which sits somewhere between a mask and ventilator on the intensity scale.

The patient will stay on the ICU until they are safe to move to a ward – one intensive care doctor told the Guardian this would probably take one to three days after coming off ventilation – where reduced intervention is needed.

But even then the struggle is still far from over. Dr David Hepburn, an intensive care consultant at the Royal Gwent hospital in Newport, wrote on Twitter: “If you end up on ITU [intensive therapy unit] it’s a life-changing experience. It carries a huge cost even if you do get better. As our patients wake up, they are so weak they can’t sit unaided, many can’t lift their arms off the bed due to profound weakness. They need to be taught to walk again, breathe again, and have problems with speech and swallowing.”

At the bare minimum, to leave the ICU, sedation will have to have worn off and their breathing must have improved to the necessary threshold. Once they are transferred on to a ward, where they are likely to spend a week or so, being able to breathe without oxygen assistance is a prerequisite for being discharged from hospital.

Facebook Twitter Pinterest A Covid-19 patient uses a tablet to speak to a relative who is unable to visit, in Milan, Italy. Photograph: Flavio Lo Scalzo/Reuters

Work will also begin in hospital on remedying the rapid weight loss and resultant weakness the patient will have suffered through muscle wastage as the body went into crisis mode during ventilation. In the first week after ventilation even sitting up in a chair can be a major first step, but as movement increases the muscles improve and get stronger day by day.

When the patient leaves hospital they will still be restricted for weeks to months in terms of exercise, due to both the damage to their lungs and their muscles. This will be the same for patients such as Ilyas, who have not been on a ventilator but instead on a Cpap or high flow nasal oxygen therapy, but their recovery time will be shorter; Ilyas said he can already feel his breathing improving on a daily basis.

Wide ranging psychological problems, from depression to PTSD (post-traumatic stress disorder) are also associated with time spent in an ICU. Patients can also suffer from hallucinations coming out of sedation, which can cause problems such as flashbacks at a later date.

“They get better in time but it may take a year and needs an army of physiotherapy, speech and language, psychology and nursing staff to facilitate this,” said Hepburn. “The few weeks on a ventilator are a small footnote in the whole process.”