A person who experiences aching on the legs during the night could be suffering from a condition called restless leg syndrome. The condition is characterized by unpleasant feeling during the night.
The main cause for restless leg syndrome is not known although there are different conditions that have been linked to it. Primary RLS, a condition where the underlying factor is not known, is known to run in families. The symptoms of RLS include leg pain, aching, itchy feeling, tingling, burning and cramps. If the situation worsens, it may lead to insomnia, as stated by the National Health Service. Severe symptoms may require medication to control the level of dopamine in the body.