Restless legs syndrome (RLS) is a neurological disorder causing uncomfortable sensations and urge to move legs, especially at rest in the evening. Restless legs syndrome significantly affects sleep quality. Iron deficiency is a major modifiable factor.
Symptoms
Diagnostic criteria (URGE):
- Urge to move legs, often with uncomfortable sensations
- Rest brings on or worsens symptoms
- Get-up-and-move provides relief
- Evening/night worse
Iron deficiency connection
Iron is critical:
- Low ferritin (under 75 ng/mL) often associated with RLS
- Brain iron levels matter even with normal serum levels
- Iron supplementation often helps
- Goal ferritin above 100 ng/mL for RLS patients
Other causes/triggers
- Pregnancy (often resolves postpartum)
- Kidney disease
- Medications (some antidepressants, antihistamines, antipsychotics)
- Caffeine, alcohol
- Sleep deprivation
- Family history
Treatment hierarchy
- Iron supplementation if ferritin low
- Lifestyle: avoid caffeine, alcohol, sedating antihistamines
- Eliminate triggering medications when possible
- Pharmacological treatment for moderate-severe
Medications
Alpha-2-delta ligands (gabapentinoids):
- Gabapentin enacarbil (Horizant) — FDA approved
- Pregabalin
- Increasingly preferred first-line
Dopamine agonists:
- Pramipexole, ropinirole, rotigotine patch
- Effective but augmentation concern (worsening over time)
- Less preferred first-line now
Other:
- Opioids for severe refractory cases
- Iron infusion if oral iron inadequate
Augmentation
Important concern with dopamine agonists. Long-term use can cause:
- Earlier symptom onset
- More severe symptoms
- Symptom spread to arms
Why dopamine agonists are increasingly second-line.
Frequently Asked Questions
Is RLS related to iron?
Yes — strong connection. Check ferritin in RLS patients.
Should I take iron for RLS?
If ferritin under 75-100 ng/mL, often helpful.
Is RLS dangerous?
Not directly but disrupts sleep significantly.
Will RLS go away?
Pregnancy-related often resolves. Idiopathic typically chronic.
What’s augmentation?
Worsening of RLS over time on dopamine agonists. Reason for cautious use.
The bottom line on RLS
Common condition with significant sleep impact. Iron supplementation important. Treatment with gabapentinoids increasingly preferred over dopamine agonists.