The National Institute for Health and Care Excellence (NICE) in the UK has guidelines about managing long-term effects of Covid 19: https://www.nice.org.uk/guidance/ng188 , which has lots of information about the common post-Covid symptoms, overall assessment, tests, management, follow-up and monitoring, referrals, etc. This guideline stresses the importance of an integrated approach to care, usually in referral centers

Read more: https://www.nice.org.uk/guidance/ng188