The four key signs of restless legs syndrome (RLS) are:
                
A strong urge to move your legs. This urge often, but not always, occurs with unpleasant feelings in your legs. When the disorder is severe, you also may have the urge to move your arms.
                
Symptoms that start or get worse when you're inactive. The urge to move increases when you're sitting still or lying down and resting.
                
Relief from moving. Movement, especially walking, helps relieve the unpleasant feelings.
                
Symptoms that start or get worse in the evening or at night.
                
You must have all four of these signs to be diagnosed with RLS.
                
The Urge To Move
                
RLS gets its name from the urge to move the legs when sitting or lying down. This movement relieves the unpleasant feelings that RLS sometimes causes. Typical movements are:
                
Pacing and walking
                
Jiggling the legs
                
Stretching and flexing
                
Tossing and turning
                
Rubbing the legs
                
Unpleasant Feelings
                
People who have RLS describe the unpleasant feelings in their limbs as creeping, crawling, pulling, itching, tingling, burning, aching, or electric shocks. Severe RLS may cause painful feelings. However, the pain usually is more of an ache than a sharp, stabbing pain.
                
Children may describe RLS symptoms differently than adults. In children, the condition may occur with hyperactivity. However, it's not fully known how the disorders are related.
                
The unpleasant feelings from RLS often occur in the lower legs (calves). But the feelings can occur at any place in the legs or feet. They also can occur in the arms.
                
The feelings seem to come from deep within the limbs, rather than from the surface. You usually will have the feelings in both legs. However, the feelings can occur in one leg, move from one leg to the other, or affect one leg more than the other.
                
People who have mild symptoms may notice them only when they're still or awake for a long time, such as on a long airplane trip or while watching TV. If they fall asleep quickly, they may not have symptoms when lying down at night.
                
The unpleasant feelings from RLS aren't the same as the leg cramps many people get at night. Leg cramps often are limited to certain muscle groups in the leg, which you can feel tightening. Leg cramps cause more severe pain and require stretching the affected muscle for relief.
                
Sometimes arthritis or peripheral artery disease (P.A.D.) can cause pain or discomfort in the legs. Moving the limbs usually worsens the discomfort instead of relieving it.
                
Periodic Limb Movement in Sleep
                
Many people who have RLS also have a condition called periodic limb movement in sleep (PLMS). PLMS causes your legs or arms to twitch or jerk about every 10 to 60 seconds during sleep. These movements cause you to wake up often and get less sleep.
                
PLMS usually affects the legs, but it also can affect the arms. Not everyone who has PLMS also has RLS.
                
Related Sleep Problems
                
RLS can make it hard to fall or stay asleep. If RLS disturbs your sleep, you may feel very tired during the day.
                
Lack of sleep may make it hard for you to concentrate at school or work. Not enough sleep also can cause depression, mood swings, and other health problems such as diabetes or high blood pressure.