Hundreds of individuals suffer from Restless Legs Syndrome (RLS), which is otherwise known as Willis-Ekbom Disease (WED). What happens here, basically, is that the individual feels uncomfortable sensations, and sometimes even pain, in their lower extremities, particularly the thigh, or feet. In certain cases, you may even feel the pain in your arms and hands.
There is not any specific time for RLS to strike, although sufferers have been known to complain about it even when they are lying down or resting. The most common description they usually have for it is an immense feeling of desire to move their limbs. It may not seem much of a hassle, but for someone who is simply trying to catch some sleep, this can prove to be highly problematic. Read more on this article: