Fatigue syndromes refer to a group of medical conditions characterized by persistent fatigue or exhaustion that is not alleviated by rest or sleep. These conditions can be difficult to diagnose and treat, and there are a number of different terms used to describe them. Some synonyms for fatigue syndromes include chronic fatigue syndrome (CFS), myalgic encephalomyelitis (ME), post-viral fatigue syndrome, and post-exertional malaise. These terms are often used interchangeably, and while there is some variation in the symptoms and severity of each condition, they all share the common feature of extreme fatigue that lasts for months or even years. Successful management of fatigue syndromes often involves a combination of medical treatment, lifestyle changes, and mental health support.