The day is observed so that stakeholders have an occasion to improve the knowledge of "the public, policymakers, and health-care professionals about the symptoms, diagnosis, and treatment of ME/CFS, as well as the need for a better understanding of this complex illness." It was chosen because it is the birthday of Florence Nightingale, who had an illness appearing similar to ME/CFS or fibromyalgia. Doctor–patient relations
Some in the medical community do not recognize CFS as a real condition, nor does agreement exist on its prevalence. There has been much disagreement over proposed causes, diagnosis, and treatment of the illness. This uncertainty can significantly affect doctor-patient relations. A 2006 survey of GPs in southwest England found that despite more than two-thirds of them accepting CFS/ME as a recognizable clinical entity, nearly half did not feel confident with making the diagnosis and/or treating the disease. Three other key factors that were significantly, positively associated with GPs attitudes were knowing someone socially with CFS/ME, being male, and seeing more patients with the condition in the last year.From the patient perspective, one 1997 study found that 77% of individuals with CFS reported negative experiences with health-care providers. In a more recent metaanalysis of qualitative studies, a major theme identified in patient discourses was that they felt severely ill, yet were blamed and dismissed. A study of themes in patient newsgroup postings noted key themes relating to denial of social recognition of suffering and feelings of being accused of "simply faking it".
Sleep problems; people may still feel weary after full nights of sleep, or may struggle to stay awake, fall asleep or stay asleep.Additionally, one of the following symptoms must be present:
Problems with thinking and memory (cognitive dysfunction, sometimes described as "brain fog")
While standing or sitting upright; lightheadedness, dizziness, weakness, fainting or vision changes may occur (orthostatic intolerance)

Other common symptoms
Many, but not all people with ME/CFS report:
Muscle pain, joint pain without swelling or redness, and headache
Tender lymph nodes in the neck or armpits
Sore throat
Irritable bowel syndrome
Chills and night sweats
Allergies and sensitivities to foods, odors, chemicals, lights, or noise
Shortness of breath
Irregular heartbeatIncreased sensitivity to sensory stimuli and pain have also been observed in CFS.The CDC recommends that people with symptoms of CFS consult a physician to rule out other illnesses, which may be treatable. Onset
The onset of CFS may be gradual or sudden. When it begins suddenly, it often follows a period of infectious-like symptoms or a known infection, and between 20 and 80% of patients report an onset resembling an infection. : 158  When gradual, the illness may begin over the course of months or years. Studies disagree as to which pattern is more common. : 158 : 181  CFS may also occur after physical trauma such as a car accident or surgery. Physical functioning
The functional capacity of individuals with CFS varies greatly. Some persons with mild CFS lead relatively normal lives with vigilant energy management; persons that are severely ill may be totally bed-ridden and unable to care for themselves.