HealthCite Connect

Restless legs syndrome: Symptoms and Causes

Restless legs syndrome typically causes an overwhelming urge to move your legs and an uncomfortable sensation in your legs.

The sensation may also affect your arms, chest and face.

It’s been described as:

  • tingling, burning, itching or throbbing
  • a “creepy-crawly” feeling
  • feeling like fizzy water is inside the blood vessels in the legs
  • a painful cramping sensation in the legs, particularly in the calves

These unpleasant sensations can range from mild to unbearable, and are usually worse in the evening and during the night causing sleep problems. They can often be relieved by moving or rubbing your legs.

Some people experience symptoms occasionally, while others have them every day.

You may find it difficult to sit for long periods of time (for example, on a long train journey).

Periodic limb movements (PLM)

More than 80% of people with restless legs syndrome also have periodic limb movements (PLM).

If you have PLM, your leg will jerk or twitch uncontrollably, usually at night while you’re asleep.

The movements are brief and repetitive, and usually occur every 20 to 40 seconds.

PLM can be severe enough to wake up both you and your partner. The involuntary leg movements can also occur when you’re awake and resting.

In many cases, the exact cause of restless legs syndrome is unknown.

When no cause can be found, it’s known as idiopathic or primary restless legs syndrome.

Research has identified specific genes related to restless legs syndrome, and it can run in families. In these cases, symptoms usually occur before the age of 40.

Dopamine

There’s evidence to suggest restless legs syndrome is related to a problem with part of the brain called the basal ganglia.

The basal ganglia uses a chemical (neurotransmitter) called dopamine to help control muscle activity and movement.

Dopamine acts as a messenger between the brain and nervous system to help the brain regulate and co-ordinate movement.

If nerve cells become damaged, the amount of dopamine in the brain is reduced, which causes muscle spasms and involuntary movements.

Dopamine levels naturally fall towards the end of the day, which may explain why the symptoms of restless legs syndrome are often worse in the evening and during the night causing sleep problems.

Underlying health condition

Restless legs syndrome can sometimes occur as a complication of another health condition, or it can be the result of another health-related factor.

iron deficiency anaemia (low levels of iron in the blood can lead to a fall in dopamine) may trigger RLS

are pregnant (particularly from week 27 until birth; in most cases the symptoms disappear within 4 weeks of giving birth)

Triggers of restless legs syndrome

There are a number of triggers that don’t cause restless legs syndrome, but can make symptoms worse.

These include medications such as:

  • antidepressants
  • some antipsychotics
  • antihistamines

Other possible triggers include:

Page last reviewed: 23 March 2022
Next review due: 23 March 2025