Do you have Secondary RLS?

When I first started blogging about restless legs, I wrote about primary and secondary RLS.

In primary RLS, the restless legs develop on their own. The condition is often hereditary.

In secondary RLS, in some cases there is a deficiency of something, for example iron. Restless legs can also go together or are the result of another condition.

In this blog I provide an overview of the situations and conditions in which someone has secondary RLS. I discuss a number of possible deficiencies. Then I will discuss other conditions that may precede RLS.

Lack of iron

The exact cause of restless legs is still unknown. However, there is considerable consensus that iron deficiency often plays a role in the development of secondary RLS.

Blood tests are the way to find out if there is such a deficiency. This concerns the value of ferritin. This value should not be less than 50 in people with RLS.

I have heard from fellow sufferers that according to their neurologist a value of 100 is the best.

In any case, it is wise to have it examined before you take an iron supplement yourself. An excess of iron is harmful and even dangerous.

Apart from an iron deficiency, other deficiencies can also contribute to the development of restless legs. Examples include magnesium, vitamin B12, folic acid and vitamin D.

When in doubt, always seek advice from a doctor or other health or nutrition expert. I myself have positive experiences with orthomolecular medicine.


The symptoms of neuropathy and restless legs are similar. The disorders are sometimes confused with each other. They also sometimes occur at the same time in the same person.

I know from several fellow sufferers that in addition to RLS, they also have a diagnosis of neuropathy.

My mother has suffered from restless legs for years. When she went to the neurologist with this a few years ago, however, only the diagnosis of neuropathy was made. That surprised me a bit.

My surprise was further increased when the neurologist prescribed her antidepressants. She was given a prescription for seroxat. This medicine is an SSRI. In short, this means that it regulates the balance of serotonin in the body.

SSRIs are known to have restless legs as a side effect. Wouldn’t this neurologist be aware of this?


People with fibromyalgia also often experience restless legs. In this case, the restless legs really do seem like a case of secondary RLS.

I know of a number of fellow sufferers that they have fibromyalgia.

I also know someone who I first knew had fibromyalgia and later found out that she also has troubled legs.

This lady once told me that she takes 400 milligrams of magnesium twice a day to counteract the symptoms of RLS. With a very good result. However, this seems like a huge amount to me.

Magnesium has a laxative effect. My gut gets upset at 400 milligrams a day, let alone double that.

The lady in question also announced at the time that she has irritable bowel syndrome. I doubt this is a coincidence in this regard.


Rheumatism can also be a reason to develop a form of secondary RLS.

I myself had to deal with osteoarthritis a few years before my restless legs became serious. I was about forty then.

For me the symptoms of arthrosis are strongly related to the weather. During the winter I suffer the most. In spring and autumn my complaints are less frequent. In the summer I am symptom free.

I don’t think there’s really a connection between my osteoarthritis and the restless legs. My suspicion is that rheumatic complaints can go hand in hand with RLS, but that this is not always the case.

Parkinson’s disease

In Parkinson’s disease, just like with restless legs, there is a disturbance in the production of dopamine.

In addition to their other complaints, people with Parkinson’s also relatively often suffer from restless legs. Conversely, the connection is not so much there. So if you have RLS, you are not at a greater risk of developing Parkinson’s.

I remember a concerned fellow sufferer who asked if she should start worrying that she might also get Parkinson’s. As said: it is possible, but you have the same chance of this as someone who does not have RLS.

In terms of medication, Parkinson’s patients are often prescribed the same drugs as people with restless legs. In fact, the drugs for RLS were originally developed for Parkinson’s disease. You get these in a lower dose for restless legs than for Parkinson’s.

I’m talking about dopamine agonists here. These fool the body a bit by mimicking the action of dopamine. Apparently that works. Actually quite amazing.


A fellow sufferer told me a while ago that she suffered from restless legs after a thyroid treatment. A clear case of secondary RLS.

She had an overactive thyroid. The treatment she received was with radioactive iodine. During such a treatment, some of the overactive thyroid hormones are destroyed. Pretty intense, I think.

In any case, it seems quite drastic to me if you develop RLS in addition to a serious condition in itself.

As for thyroid disorders where people get secondary RLS, I read more often about an underactive thyroid than about an overactive thyroid.

There may be a link between an underactive thyroid and the absorption of iron and vitamin B12.

More research is needed.


Kidney problems that are in an advanced stage sometimes lead to secondary RLS.

Kidney damage causes low iron levels. That could be the underlying problem of the restless legs.

Medications for kidney damage or kidney failure do not mix well with restless leg medications.

Extra frequent dialysis may help to reduce symptoms of RLS.

Cardiovascular diseases

Lists of diseases and disorders that can cause a form of secondary RLS often include cardiovascular diseases.

I immediately think of claudicatio intermittent. That’s a vascular disease. Claudicatio intermittent and restless legs are sometimes confused. However, they are different conditions.

As far as I know, this disease and restless legs don’t necessarily often occur at the same time in one person.

Another thing is that RLS may increase the risk of cardiovascular disease. In that case, the connection would be the other way around.

In my blog about cardiovascular disease I already wrote that my provisional final conclusion here is that there may be an interaction between RLS and cardiovascular disease.

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