First of all I would like to know in which area does it pain in legs..
If it's the calf area and u are having cramps then the common causes are over exertion , prolonged standing, calcium , vitamin and even water deficiency. Other cause may be thyroid disorder.
My advise is to drink lots of water, electrol, take calcium and multivitamin specially vit E . and get ur thyroid checked.
If the pain is in the joints then it can be osteoarthritis . take paracetamol for pain and any pain killer gels.
Visit your rheumatologist. He/she will be able to guide you in a better way after proper check up.
Wishing you a speedy recovery.