Brief Answer:
Hi kindly read below
Detailed Answer:
Hi,
Sudden onset of fatigue and lethargy could be because of vitamin deficiency, sedentary lifestyle or hormonal imbalance. I would recommend a routine blood test including complete blood count, vit d , vit b12, lipid profile and thyroid function test to rule out any deficiency. Kindly revert back with reports for further management.
Regards.