Read about the possible causes of restless legs syndrome (RLS), including genes, problems with dopamine, and other underlying health conditions, such as iron deficiency anaemia.
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.
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.
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. This is known as secondary restless legs syndrome.
You can develop secondary restless legs syndrome if you:
There are a number of triggers that don't cause restless legs syndrome, but can make symptoms worse. These include medications such as:
Other possible triggers include: