Chronic fatigue is an insidious process which affects many people and is very difficult to diagnose and treat.

Recent research suggests that fatigue, which commonly occurs in combination with other symptoms such as vague aches or nervousness, may be caused by unrecognised infections to hidden biochemical or neuro-hormonal abnormalities (1).

Symptoms of fatigue are worsened by physical or psychological stress, with consequent self-prescribed reduction in activity, so that patients often retreat into a sedentary life style.

It has recently been suggested that chronic fatigue may be related to neural functional pathology(2). A recent scientific paper(3) provides evidence that this condition may be caused by an imbalance of the autonomic control of the circulation.

The methods used to investigate this phenomenon include the analysis of heart rate variability where the investigators found a previously unrecognised abnormality of autonomic control of heart rate in patients complaining of unexplained fatigue, suggestive of sympathetic predominance and vagal withdrawal.

The use of  heart rate variability analysis can be used to measure the neurohormonal status of patients and provide a guide to management using both physical and pharmacological intervention.