ITV News Meridian's Tom Savvides reports.
Those suffering with Long Covid in Sussex are among some of the first in the world to take part in a ground-breaking study into the illness.
Researchers are looking into how the illness affects the brain, with thousands of people believed to have been left with long term memory problems and extreme fatigue after contracting coronavirus.
A pioneering study at the Princess Royal Hospital in Haywards Heath will use MRI scanners to analyse the brains of those suffering from long Covid.
The results will be used to come up with therapies to help people return to normal daily activities.
Jason Lim caught Covid-19 last year and since then he says he has been unable to function properly.
Simple tasks such as showering daily, going for a walk or cooking a complex meal leave him feeling tired and drained.
Some of the most common symptoms of Long Covid include:
Problems with memory and concentration - often referred to as "brain fog"
Dr Dennis Chan, Consultant Neurologist
The study is expected to last for two years, after which time doctors should have enough information to come up with a solution to Long Covid.