this is common complains now a days,if your work is heavy,physically or mentally then you may get pain in the legs at night,
Lack of exercise due to lack of time also gives this problem.
If you are smoker,quit smoking
There may be some vascular cause and due to this there is less blood flow to this area and can cause this complain.For this you contact your doctor.
So to recover from this problem,stop smoking if you smoke, do some exercise like running,walking, swimming etc,take more milk,green vegetables,fruits etc.