Brief Answer:
Can be due to nutritional deficiency.

Detailed Answer:
Hello,
Thanks for posting your query.

Most likely causes for fatigue in you may be due to overwork and lack of sleep.
Boredom, anxiety and depression also cause fatigue.
Apart from these, lack of iron, calcium, B12, FOLIC ACID and hypothyroidism may also result in fatigue.
I advise you for
-Try taking out some time to do yoga
-Plenty of water
-Take calcium,iron and B complex vitamins for few weeks
-Get your hemoglobin and hypothyroidism checked up
-Change of season to summer also drains you.
Do deep breathing daily for five minutes before you go to sleep.
Generalised aches of leg muscles and weakness are often found in vitamin D and magnesium deficiency.

I suggest you to consult an endocrinologist and get prescribed vitamin D and magnesium supplements. Your symptoms should improve with that. Also eat magnesium rich foods like bananas, beans, chickpeas, fish, nuts, soybeans, spinach etc which are natural sources of magnesium.

I hope this answers your query.
In case you have additional questions or doubts, you can forward them to me, and I shall be glad to help you out.
Wishing you good health.
Regards.
Dr. Praveen Tayal.
For future query, you can directly approach me through my profile URL http://bit.ly/Dr-Praveen-Tayal

---

Brief Answer:
Do get a few blood tests done.

Detailed Answer:
Hello.
Thanks for writing again.
You can start with a multivitamin and multimineral supplement like Health OK or Absolute 3G. Do get specific tests done after consulting your physician and in case the levels are low then start with proper supplements.
Hope my answer is helpful.
Do accept my answer in case there are no further queries.
Regards.

---