From MEpedia, a crowd-sourced encyclopedia of ME and CFS science and history

A relapse in myalgic encephalomyelitis/chronic fatigue syndrome is .[1][2]

NHS definition[edit | edit source]


A sustained and marked exacerbation of symptoms lasting longer than a flare-up and needing a substantial and sustained adjustment to the person's energy management. It may not be clear in the early stages of a symptom exacerbation whether it is a flare‑up or a relapse. Relapses can lead to a long-term reduction in the person's energy limits.[1]

ME/CFS:diagnosis and management. NICE guideline (2021).

The UK's National Health Service definition of a relapse can be found within the 2021 NICE guidelines.[1]

International Consensus Criteria[edit | edit source]

The International Consensus Criteria does not define what a relapse is, but states that relapses can last for days, weeks or longer.[2]

Impact[edit | edit source]

The impact of a relapse varies from person to person. But most will find that they will have to revisit any coping mechanisms they have used prior to relapse to manage symptoms or avoid triggers. Energy levels will be heavily depleted and it is likely to take several weeks if not months or longer to return to pre-relapse levels.[citation needed]

Similarly, with symptoms it will take a long time for them to ease, and this in turn goes to aggravate energy levels.[citation needed]

Notable studies[edit | edit source]

See also[edit | edit source]

Learn more[edit | edit source]

References[edit | edit source]