Although, we are often presented with a major illness, apparently of limited duration, close scrutiny of the medical histories of many patients reveals an evolution of symptoms over several years.
Patients often discount or fail to report long-term, chronic or recurrent symptoms.
Symptoms of a mild ADS are often intermittent and ambiguous. A new factor such as move to a new home, a change in eating habits, a viral infection, an injury, childbirth, or a drug reaction may precipitate sudden collapse into a more disabling illness. For example, a 34 year old woman presented with an illness of 10 months duration. A consultant's medical history stated that she was well until 10 months previously when she developed a flu-like illness with lymph node swelling, fatigue, aching, and sore throat. When she did not recover as expected, extensive investigations for infections and other problems were inconclusive.