Lethargy refers to persistent tiredness and is usually a symptom of another illness rather than being an ailment itself. The common causes of lethargy are:
- Anaemia, diabetes and thyroid disease
- Stress and depression
- Chronic fatigue syndrome
Occasionally, lethargy can even be a sign of serious illness, so consult your doctor if you suddenly experience fatigue. Blood tests need to be conducted to rule out diabetes, anaemia, thyroid disease etc.