Hello and hope you are doing well.
Restless legs syndrome is a sleep disorder, where there is an odd sensation in the legs during sleep causing the individual to move, which relieves the sensation. This disorder can cause inadequate sleep leading to fatigue and daytime sleepiness. The cause is not known. They can be diagnosed with a sleep study and medications help to control them.
I would advise you to consult a sleep specialist who would assess with first a sleep questionnaire, and then he may ask for a polysomnogram, which is an overnight sleep study.
Hope this helped and do keep us posted.