Restless Legs Syndrome (RLS)

🔍 When to Suspect

An irresistible urge to move the legs with unpleasant sensations, which begins or worsens during rest, is relieved by movement, and is worse in the evening or at night

From the full topic in The Ocean Library: Restless Legs Syndrome (RLS)

🧭 When to suspect

Restless legs syndrome (RLS), also called Willis–Ekbom disease, is a common sensorimotor disorder defined by an irresistible urge to move the legs, usually accompanied by unpleasant creeping, crawling, pulling or aching sensations. It is a clinical diagnosis – there is no confirmatory test – resting on five essential criteria.

Suspect it when symptoms are worse at rest, relieved by movement, and worse in the evening or at night. The key primary-care task is to separate primary (idiopathic) disease, which is lifelong and often familial, from secondary RLS driven by a reversible cause – chiefly iron deficiency, chronic kidney disease (CKD), pregnancy, and culprit medications. The five criteria are remembered as URGE.

Essential criterion (all five required)	Detail / clinical note
U – Urge to move the legs	Usually accompanied by uncomfortable sensations (creeping, crawling, pulling, aching, itching); occasionally the urge occurs without sensation.
R – Worse at Rest	Begins or worsens during rest or inactivity, such as lying or sitting.
G – Relieved by movement (Getting up)	Partially or totally relieved by walking or stretching, at least for as long as the activity continues.
E – Worse in the Evening/night	Symptoms are worse in the evening or at night, or occur only then.
Not better explained by a mimic	Not solely accounted for by another condition – e.g. nocturnal leg cramps, positional discomfort, arthralgia, venous stasis, peripheral neuropathy or habitual foot-tapping.

All five criteria must be present to diagnose RLS. Before reaching for a prescription, the two highest-value actions are to check iron status and to review the drug list for agents that provoke or worsen symptoms.

⚠️ Common pitfall Labelling every night-time leg symptom as RLS. Nocturnal leg cramps (painful, palpable muscle contraction with no urge to move), peripheral neuropathy (constant burning or numbness, not relieved by movement) and akathisia (generalised, often drug-induced inner restlessness) are common mimics. The discriminator is the URGE pattern – an urge to move that is relieved by movement, worse at rest, and worse in the evening.

Source: NICE · International RLS Study Group (IRLSSG)

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