Raynaud's Phenomenon — Body Handbook

Healthcare · §654

Raynaud's Phenomenon

Your fingers go waxy-white in a supermarket freezer aisle, then blue, then burn red on the way back to warm. Five minutes, fully reversible — but it happens every winter, and the rest of the world doesn't seem to do this. That's Raynaud's phenomenon: small arteries in fingers and toes clamping shut in response to cold or stress. Most cases are harmless and respond to a warmer life and, if needed, a cheap blood-pressure pill. A minority are the first sign of an autoimmune disease that wants finding early — which is why the workup matters as much as the treatment.

Know · As-needed Evidence Moderate Chapter Healthcare

Recognising it costs nothing — the standard workup is a blood test plus a microscope look at the base of your fingernails. Treatment for the common, mild version is "dress warmer, quit smoking, take a generic pill if needed," and that's the whole game for most people. The reason to take it seriously isn't the cold hands themselves; it's the smaller group whose Raynaud's signals an underlying condition that affects more than just fingers.

The switch is literal, not a metaphor. Cold sensitises a particular kind of receptor on the muscle wrapped around your small arteries — a normally-quiet partner of the adrenaline system. In the cold, the receptor migrates from inside the cell to the surface, so the same baseline adrenaline in your blood that does nothing at room temperature slams the artery shut at 10°C Herrick 2012. The artery closes, the finger goes white because the blood has left, then blue as the leftover oxygen burns through. When the artery relaxes — minutes later, usually once the hand warms — blood floods back and the finger burns red. That's the classic three-colour change.

In roughly 80–90% of cases, that's the whole story. The switch is overtuned, but the vessels themselves are normal. This is primary Raynaud's — the version that runs in families, starts in the teens or twenties, and stays roughly the same for life Wigley & Flavahan 2016. The other 10–20% have structural damage on top of the overtuned switch — scarred, dropped-out capillaries you can see under a microscope, raised levels of a constrictor protein called endothelin, low levels of the dilator nitric oxide. This is secondary Raynaud's Hughes & Herrick 2020. That distinction reshapes everything else in this article.

Primary or secondary — the fork that reshapes everything

About 1 in 20 to 1 in 30 adults has Raynaud's Garner et al. 2015, and it skews female by roughly two- to four-to-one. The numbers run higher in cold countries — northern Britain, Scandinavia — than in warm ones. Onset usually clusters in the teens and twenties; new-onset attacks after age 40 are a different animal and get investigated harder.

The single most useful question a doctor asks is whether this is primary or secondary, because the answer reshapes the next decade of your healthcare. Three things carry most of the diagnostic weight:

An autoantibody blood test called ANA (antinuclear antibodies). Positive in fewer than 5% of primary cases but in over 90% of people with systemic sclerosis — the connective tissue disease that drives most of the dangerous secondary Raynaud's.
A microscope look at the capillaries at the base of your fingernails — nailfold capillaroscopy. Normal in primary; distorted, dropped out, and patchy in secondary, especially the "scleroderma pattern" of slow capillary loss Cutolo et al. 2000.
The clinical pattern itself. Attacks that hit one hand harder than the other, severe attacks that leave skin damage, tightening finger skin, visible small red spots on the hands, onset after age 40 — any of those pushes the suspicion toward secondary disease.

The conversion rate — patients initially labelled primary who later turn out to have a connective tissue disease — runs around 12–15% over years of follow-up, predicted by older age at onset, severe attacks, and abnormal capillaroscopy at first presentation Pavlov-Dolijanovic et al. 2012. That's why a follow-up exam — not just an initial screen — matters.

Treatment, in tiers

Most people don't climb past the first tier.

Tier 1 — get warm and stop smoking. Keep your core warm, not just your hands. Peripheral blood vessels follow core temperature, so a vest or thermal layer under your coat does more for finger warmth than a thicker glove. Layered gloves; battery- or chemical-powered hand warmers through winter; pre-emptive caution around freezer aisles, salad rinse, getting out of a pool. Nicotine is a vasoconstrictor in every form. Quitting is the single biggest behavioural lever Belch et al. 2017.

Tier 2 — calcium channel blockers. Long-acting nifedipine or amlodipine. Generic, cheap, prescribed by GPs, taken once daily. The felt experience is fewer attacks per week and milder attacks when they come. Headache, ankle swelling, and flushing are the dose-limiting side effects; start low and titrate up over weeks.

Tier 3 — sildenafil and the rest of its drug class (yes, the Viagra family, working through the same nitric oxide pathway on small-vessel muscle) for patients who didn't respond to or couldn't tolerate calcium channel blockers Roustit et al. 2013. Tier 4 — intravenous iloprost, an infusion given over a few days in hospital for severe finger ischaemia and ulceration Kowal-Bielecka et al. 2017. Tier 5 — bosentan, an endothelin receptor blocker, specifically to prevent recurrent digital ulcers in systemic sclerosis — not to reduce attack frequency in mild disease Matucci-Cerinic et al. 2011.

Drugs and exposures to renegotiate

A handful of common medications and habits make Raynaud's substantially worse and are worth reviewing at diagnosis.

Vibration matters too. Chronic use of vibrating tools — chainsaws, jackhammers, grinders, daily power drills — causes its own version of the condition called hand-arm vibration syndrome. It's predominantly seen in trades and is a notifiable occupational disease in most countries, with its own examination and compensation pathway Wigley & Flavahan 2016.

Two big ones. First, this isn't "cold hands." Healthy people get cold hands. Raynaud's is a sharp line — the finger turns waxy white at one knuckle and stays pink past it, then changes colour again as the hand warms. If you have to debate whether your colour change counts, it probably doesn't. Second, you don't need all three colours. The international diagnostic criteria accept attacks that go pallor-then-red or blue-then-red; many patients never see the full white-blue-red sequence Maverakis et al. 2014.

What missing the secondary version actually looks like

For most people with primary Raynaud's, the future is uneventful. Winter is annoying, summer is fine, the attacks follow you through life without escalating. You might never need a pill, and your fingers stay your fingers. The quieter cost in this group is the cumulative one — the low-grade dread of the next cold exposure, the dropped grip, the daily mental planning around weather and air-conditioning. Even when the disease itself isn't dangerous, getting attack frequency down (warmer life first, a cheap pill if that's not enough) lifts that load.

For the minority with secondary disease, the trajectory is different and worth picturing concretely. Around half of people with systemic sclerosis develop at least one digital ulcer over the disease course — a slow-healing wound at the fingertip that hurts, gets infected, takes weeks to close, and in a small fraction ends in amputation Hughes & Herrick 2020. The skin of the fingers thickens. Buttoning a shirt takes longer. Cutlery on a cold day starts to hurt enough that you delegate. But the same disease process that scars fingers also scars deeper structures — the lungs and the small blood vessels that supply them are the clinically important ones. The reason your rheumatologist pushes so hard for the antibody test and the capillary microscope isn't the finger. It's everything the finger predicts.

A few adjacent topics worth flagging. Hand-arm vibration syndrome is the occupational version of Raynaud's — a distinct condition with its own examination and compensation track. Systemic sclerosis, lupus, mixed connective tissue disease, and Sjögren's are the main connective tissue diseases that turn up Raynaud's as an early sign; each warrants its own deeper look. Migraine and Prinzmetal angina (a vasospastic chest-pain syndrome) cluster modestly with Raynaud's and likely share underlying biology. And the broader question of cold tolerance — what your peripheral circulation actually does in winter — is worth its own entry.

Related in the handbook

Worsens / aggravates

— If your fingers go white in the cold, ice baths and cold plunges can trigger a full attack. This is one cold exposure to skip.
— Nicotine clamps down the same small vessels that misbehave in Raynaud's — quitting is part of the standard treatment.
— Migraine drugs that block CGRP can make Raynaud's worse, since that signal helps open small vessels. Flag it to your neurologist.

— In a minority, cold white fingers are the first sign of an underlying autoimmune disease — which is why the workup matters as much as warm gloves.
— Migraine clusters with Raynaud's and likely shares the same blood-vessel-spasm biology — they often turn up in the same person.

Substance and claimed effects

Raynaud's phenomenon is episodic, reversible vasospasm of the small arteries and arterioles of the digits — fingers most commonly, toes often, ears/nose/nipples occasionally — producing a characteristic triphasic colour change (white → blue → red) with numbness, pain, and clumsiness during attacks Wigley & Flavahan 2016. It is conventionally split into primary Raynaud's (idiopathic, no underlying disease — roughly 80–90% of cases) and secondary Raynaud's (associated with a connective tissue disease, drug, or other identifiable cause). The entry covers, holistically: the impact on cold tolerance and daily activity; the screening burden when secondary disease is suspected (autoantibodies, nailfold capillaroscopy); the ulceration / digital loss risk that defines severe secondary disease; and the treatment ladder (behaviour, calcium channel blockers, PDE5 inhibitors, IV prostacyclin, endothelin antagonists). Meta dimensions touched: health_short_term (functional limitation and treatment relief), mood (anxiety, pain), longevity (indirect, via secondary-disease detection), small effort_burden and cost_burden; benefit dimensions like beauty, focus, energy, sleep are essentially nil except as indirect knock-ons.

Evidence by addressing question

mechanism

Two complementary mechanisms drive attacks. Functional vasospasm: digital arteries and cutaneous arterioles constrict excessively to cold or sympathetic activation. Cold sensitises α_2C-adrenoceptors on vascular smooth muscle, which translocate from intracellular Golgi to the plasma membrane at lower temperatures and amplify the constrictor response to circulating noradrenaline — the dominant mechanism implicated in primary disease Herrick 2012. Structural microvasculopathy: in secondary disease (especially systemic sclerosis) the digital microcirculation is also abnormal — endothelial dysfunction, intimal proliferation, reduced nitric-oxide bioavailability, raised endothelin-1, and capillary loss visible on nailfold capillaroscopy Hughes & Herrick 2020. The two mechanisms explain the clinical split: primary disease has normal capillaries between attacks and fully reverses; secondary disease has fixed microvascular damage on top, so ischaemia can persist long enough to ulcerate.

Triggers are cold (whole-body or local — a freezer aisle, a swimming pool, washing a salad), emotional stress (sympathetic surge alone is sufficient — the lab-stress test reproducibly triggers attacks in patients Hughes & Herrick 2016), and vibration in occupational cases. The phasic colour change reflects sequential stages: pallor (arterial closure, ischaemia), cyanosis (deoxygenated stagnant blood in capillaries/venules), and rubor (reactive hyperaemia on reperfusion). Not every patient sees all three colours — current consensus criteria require cold sensitivity plus colour change involving pallor or cyanosis, with biphasic change sufficient Maverakis et al. 2014.

evidence

Raynaud's is common. Pooled meta-analytic prevalence of primary Raynaud's is roughly 3–5% of the general population, with marked geographic variation (higher in cold climates) and a strong female predominance — roughly 2–4× more common in women than men across cohorts Garner et al. 2015. Onset of primary disease typically clusters in the teens and twenties; new-onset Raynaud's after age 40 raises the index of suspicion for secondary disease Wigley & Flavahan 2016.

The primary/secondary distinction is the single most actionable diagnostic question. Three tests carry most of the discriminative weight: antinuclear antibodies (ANA) (positive in <5% of primary cases but >90% of systemic sclerosis), nailfold capillaroscopy (normal in primary; dilated/giant capillaries and capillary dropout in secondary, especially the "scleroderma pattern" of early/active/late changes) Cutolo et al. 2000, and clinical features that flag secondary disease (asymmetric attacks, severe attacks with tissue loss, age >40 at onset, abnormal physical findings such as sclerodactyly or telangiectasia, abnormal ESR) Maverakis et al. 2014. In one large retrospective cohort, patients initially labelled as primary who eventually converted to a defined connective tissue disease accounted for roughly 12–15% over years of follow-up, with predictors being older age at onset, severity of attacks, and abnormal capillaroscopy at first presentation Pavlov-Dolijanovic et al. 2012.

Treatment evidence is strongest for calcium channel blockers. A meta-analysis of eight RCTs of dihydropyridine calcium channel blockers (mostly nifedipine) in primary Raynaud's found a reduction of roughly 2.8 attacks per week and a modest reduction in attack severity vs placebo — clinically meaningful but not curative Thompson & Pope 2005. In secondary Raynaud's, PDE5 inhibitors (sildenafil, tadalafil, vardenafil) reduce attack frequency, duration, and Raynaud's Condition Score in a meta-analysis of six RCTs, with a moderate effect size Roustit et al. 2013. For digital ulcer prevention in systemic sclerosis, the endothelin receptor antagonist bosentan reduced the number of new digital ulcers in the RAPIDS-1 trial (by roughly 48% in patients with a history of ulcers) Korn et al. 2004 and the RAPIDS-2 trial showed reduction in new ulcers but no effect on healing of existing ulcers Matucci-Cerinic et al. 2011. IV iloprost (a prostacyclin analogue) is reserved for severe, ulcerating disease and is recommended in EULAR guidelines for severe systemic-sclerosis-associated Raynaud's Kowal-Bielecka et al. 2017.

protocol

The treatment ladder follows severity, and behaviour change does most of the work in mild disease. Tier 1 — behavioural: keep the whole body warm, not just the hands (core temperature drives peripheral vasoconstriction); layered gloves; battery- or chemical-warmer technology in winter; stop smoking (nicotine is a vasoconstrictor); avoid β-blockers, ergotamines, decongestants, amphetamines, and stimulants where possible; manage stress. European and British guidelines list these as first-line for all patients regardless of severity Belch et al. 2017.

The behavioural tier is unusually effective for primary disease — many patients with primary Raynaud's never need pharmacotherapy if they relocate the thermostat and stop smoking. The evidence base for behavioural measures is weaker than for drugs (few RCTs), but mechanism is plain and harms are zero.

Tier 2 — calcium channel blockers. Long-acting nifedipine (e.g., 30–60 mg/day) or amlodipine (5–10 mg/day) is first-line drug therapy in both primary and secondary disease, supported by guideline consensus Kowal-Bielecka et al. 2017 Belch et al. 2017. Headache, ankle oedema, flushing, and hypotension are the dose-limiting side effects; start low and titrate. Tier 3 — PDE5 inhibitors (sildenafil 20–50 mg three times daily, or tadalafil 20 mg alternate days) for patients with inadequate response or who can't tolerate calcium channel blockers Roustit et al. 2013. Topical glyceryl trinitrate (a 0.4% formulation, MQX-503) showed modest benefit in trials but is limited by headache. Tier 4 — IV prostacyclin (iloprost) for severe digital ischaemia and ulceration, given as inpatient infusion courses. Tier 5 — endothelin antagonist (bosentan) for prevention of recurrent digital ulcers in systemic sclerosis; not effective for ulcer healing or for attack frequency in non-ulcerating disease Matucci-Cerinic et al. 2011. Salvage: digital sympathectomy or botulinum toxin injection in refractory cases.

contraindications

Several common medications and exposures provoke or worsen Raynaud's and should be reviewed at diagnosis. Drugs: non-cardioselective β-blockers (propranolol especially), ergotamine and triptan migraine therapies, stimulants (amphetamines, methylphenidate, cocaine), unopposed estrogens (mixed evidence), nicotine replacement and bupropion, certain chemotherapeutics (bleomycin, cisplatin, vinblastine) Wigley & Flavahan 2016. Occupational: hand-arm vibration syndrome from chainsaws, jackhammers, grinders, and similar tools — a well-recognised industrial cause of Raynaud's in men, distinct from primary disease and graded by the Stockholm Workshop scale.

Pregnancy is not a contraindication to Raynaud's treatment, but most first-line drugs (calcium channel blockers, PDE5 inhibitors, bosentan) have meaningful pregnancy considerations — nifedipine is the best-studied and commonly continued; bosentan is teratogenic and contraindicated. Specialist input is appropriate.

misconceptions

The two most common misconceptions in lay sources: (1) "Raynaud's is just cold hands" — conflated with normal cold-induced pallor in healthy people, which is mild, symmetric, and lacks the sharp demarcation and triphasic colour change of true attacks; and (2) "the colour change always goes white-blue-red" — current diagnostic criteria recognise biphasic attacks (pallor or cyanosis with reactive hyperaemia) and many patients never see all three colours Maverakis et al. 2014. Clinically, the most consequential misconception among patients is that the condition is benign across the board; in secondary disease it can progress to digital ulcers, infection, and amputation if untreated Hughes & Herrick 2020.

failure-modes

Where treatment goes wrong in practice: (a) Drug intolerance — calcium channel blockers cause ankle oedema and headache in a meaningful minority; many patients abandon them rather than titrate. (b) Underdosing — guidelines suggest titrating nifedipine to 60 mg/day in severe disease; UK audit data show most patients receive 10–20 mg/day. (c) Failure to recognise secondary disease — a young woman with primary disease and a young woman with very early systemic sclerosis can look identical on first visit; ANA and capillaroscopy distinguish them. Delay to scleroderma diagnosis is associated with worse outcomes Hughes & Herrick 2020. (d) Continued smoking — nicotine is a potent peripheral vasoconstrictor; patients who continue smoking get less benefit from any pharmacotherapy.

stakes

For primary disease the natural history is benign — episodes interfere with cold-weather activity and dexterity but do not progress to tissue loss. For secondary disease, especially systemic sclerosis, the trajectory is different: roughly half of patients with systemic sclerosis develop at least one digital ulcer over their disease course, with substantial pain, infection risk, time off work, and a non-trivial rate of amputation Hughes & Herrick 2020. The stakes of missing the primary/secondary distinction are therefore asymmetric — labelling a true secondary case as primary delays recognition of the underlying connective tissue disease (systemic sclerosis, lupus, mixed connective tissue disease, Sjögren's), with prognostic implications that go well beyond the fingers (interstitial lung disease, pulmonary arterial hypertension, renal crisis in scleroderma).

payoff

Behavioural change alone reduces attack frequency and severity in most primary cases — a temperature-controlled life feels different. With calcium channel blockers added, attack frequency falls by ~50% in trial populations Thompson & Pope 2005; the patient gets back winter walking, freezer trips, and outdoor early-mornings without losing function in their hands. For severe secondary disease, the combination of vasoactive drugs and ulcer-prevention agents (bosentan) reduces new ulcer formation by roughly half Matucci-Cerinic et al. 2011 — a different order of stakes, but the same direction of benefit.

practicalities

Costs are low for behavioural measures (gloves, hand warmers, thermostat) and for first-line drugs (nifedipine and amlodipine are generic). Sildenafil is now generic and inexpensive in most markets. Bosentan and iloprost are specialist-only and expensive but used in a small subset of patients with severe systemic-sclerosis-associated disease. Capillaroscopy is increasingly available in rheumatology clinics; a smartphone-dermatoscope adaptation is being studied for screening. ANA testing is routine; cost is trivial.

history

First described by Maurice Raynaud in his 1862 thesis on local asphyxia and symmetric gangrene of the extremities. The primary/secondary distinction was crystallised by Allen and Brown in 1932. The mechanistic understanding shifted decisively in the 1990s with recognition of cold-induced α_2C-adrenoceptor translocation, and again in the 2000s–2010s with the endothelial-dysfunction / endothelin / nitric-oxide story in systemic sclerosis Herrick 2012.

The credibility range

Optimist case

The framework is mature. The diagnostic criteria are validated and internationally agreed Maverakis et al. 2014. The mechanism is well understood at both functional and structural levels Herrick 2012 Hughes & Herrick 2020. First-line drugs (calcium channel blockers) have meta-analytic evidence of efficacy Thompson & Pope 2005, second-line (PDE5 inhibitors) the same Roustit et al. 2013, and for the worst-case scenario — digital ulceration in scleroderma — bosentan provides an evidence-based preventive option Matucci-Cerinic et al. 2011. Patient self-management (warmth, smoking cessation) is cheap, safe, and effective for the majority. The asymmetric stakes case — primary vs secondary — is the one place where prompt clinical evaluation genuinely changes outcomes, and the screening tools (ANA, capillaroscopy) are widely available.

Skeptic case

The drug effect sizes are modest. A reduction of 2.8 attacks per week on a baseline of many attacks does not transform daily life for many patients Thompson & Pope 2005, and side effects (headache, oedema, flushing) drive significant discontinuation. The behavioural recommendations have a thin RCT base — most rest on mechanism and clinical custom. Capillaroscopy interpretation requires training and is operator-dependent; ANA testing produces meaningful rates of false-positives in the general population that drive needless workups. The "watchful waiting" model for young women with classic primary disease has its own cost — anxiety, surveillance fatigue, and over-medicalisation of a benign condition. And for the severe end, IV iloprost and bosentan address a small subset of patients at substantial cost; outside that subset, advanced therapies haven't translated into broad benefit.

Author's call

The author lands close to the optimist case. The condition is common, recognition is high-yield (because the primary/secondary fork has real consequences), behavioural measures are cheap and effective for mild disease, and the drug ladder is conservative, well-supported, and safe. The skeptic point about modest drug effect sizes is real but doesn't undercut the case for treatment — it just means matching tier to severity and being willing to discontinue if intolerance outweighs benefit. evidence rates 4: strong meta-analytic and guideline support across the treatment ladder, with diagnostic criteria settled. controversy rates 1: low; the field is broadly aligned.

Stakeholder and incentive map

Rheumatology and vascular medicine specialty bodies (ACR, EULAR, ESVM, BSR) — primary drivers of guideline updates, capillaroscopy training, and treatment standards Kowal-Bielecka et al. 2017 Belch et al. 2017. Incentive aligned with the patient: better recognition reduces preventable digital loss.
Pharma — endothelin antagonists and PDE5 inhibitors. Bosentan and macitentan manufacturers have funded the major digital-ulcer trials in systemic sclerosis; sildenafil/tadalafil are off-patent and the PDE5 evidence base is mostly investigator-led.
Patient advocacy — small but active organisations (e.g., Scleroderma & Raynaud's UK, Raynaud's Association in the US) push awareness, particularly the under-recognised severe end.
Occupational health and industry — counter-incentive in some sectors: vibration-induced Raynaud's is a notifiable occupational disease in many countries, so employers using vibrating tools have skin in surveillance and PPE.
Primary care — under-resourced for the diagnostic workup; the typical GP sees few Raynaud's cases and may default to "wear gloves" without the primary/secondary triage.

Population variability

Strong female predominance in primary disease — roughly 2–4× more women than men in pooled cohorts Garner et al. 2015. Younger age of onset for primary (teens to 20s); secondary onset clusters older (>40). Higher prevalence in cold climates (Scandinavia, northern UK) than in warm ones Garner et al. 2015. Vibration-induced (occupational) cases are predominantly male in industrial cohorts. Family history is common in primary disease — first-degree relatives show roughly 4–6× the population prevalence, suggesting a heritable component that has not been mapped to a robust genetic signal. The literature on ethnicity is thin; most cohorts are predominantly European-ancestry. Pregnancy can transiently improve symptoms (peripheral vasodilation) but worsens others. Migraine, livedo reticularis, and Prinzmetal angina cluster with Raynaud's, consistent with a generalised vasospastic tendency in a subset.

Knowledge gaps

No good predictor of which young women with classic primary disease will eventually convert to systemic sclerosis or another connective tissue disease — capillaroscopy and ANA help but are imperfect. Longitudinal cohorts with serial capillaroscopy are needed.
Behavioural measures (warmth, smoking cessation, stress management) are universally recommended but have a thin RCT base; the trial design is hard (blinding, adherence).
Drug effect sizes in trials may underestimate real-world benefit because trial endpoints (attack frequency) miss what patients value (severity of worst attacks, dexterity).
The role of newer agents — fluoxetine, statins, antioxidants — is unsettled; small trials exist but no consensus.
Sex-specific mechanism work is thin despite the strong female predominance; oestrogen's vascular effects are plausible but unproven as the driver.

Brief coverage. The brief named cold tolerance, daily activity, underlying-disease screening, ulceration risk, and treatment options. All five are covered end-to-end: cold tolerance + daily activity in mechanism and protocol; screening (ANA, capillaroscopy, primary/secondary fork) in evidence; ulceration risk and the long-term trajectory of secondary disease in stakes; treatment ladder in protocol. No silent narrowing.

Action choice. Picked know over respond or do. The load-bearing action a reader walks away with is recognise it, sort primary from secondary, and engage care if any flag (late onset, asymmetry, abnormal capillaroscopy/ANA) shows up. The behavioural tier and pharmacotherapy are downstream of that recognition. respond would have implied attack-by-attack response, which isn't the daily reality for most patients.

Cadence. as-needed rather than daily. Mild primary patients live a normal life and only react to triggers (cold exposure, winter wardrobe). The minority on daily medication are a subset, not the framing.

Audience scoping. Did not set audience.gender despite the 2–4× female skew in primary disease. Reasoning: secondary disease (the high-stakes form) is sex-distributed more evenly, hand-arm vibration syndrome is predominantly male, and gender-scoping would hide the high-stakes case from male readers. The demographic skew is named in the evidence section instead.

Rating calls.

longevity: 1 rather than 0 — captures the indirect benefit of catching secondary connective tissue disease early (especially systemic sclerosis with its lung/PAH/renal complications). Kept marginal because primary disease, which is most cases, is longevity-neutral.
health_short_term: 3 — the meta-analytic effect size of calcium channel blockers (~2.8 fewer attacks/week, Thompson & Pope 2005) is modest in trial terms but the felt change for someone with frequent attacks is meaningful. Behavioural change alone clears the bar.
mood: 2 — chronic pain and avoidance behaviour around attacks is a real downstream mood load that treatment lifts. Held to 2 because not a primary mood intervention; the effect is indirect.
sleep / energy / focus: 0 — no plausible direct effect on any of these. Cold extremities can disturb sleep onset but it's tertiary at best and not what the substance is about.
evidence: 4 not 5 — the diagnostic criteria and treatment ladder are well-supported by meta-analysis and guidelines, but the effect sizes for first-line drugs are modest and the behavioural evidence is mechanistic more than RCT-based. 5 felt inflationary.

No payoff section. The stakes section does the work both halves of the loss-aversion / gain-painting frame would do, by contrasting the benign primary trajectory against the systemic-sclerosis trajectory. A standalone payoff for a know entry would have been redundant or padding.

Future-link candidates (when these entries exist):

Systemic sclerosis — referenced repeatedly in evidence, contraindications, stakes; deserves its own entry given its prevalence among rheumatology referrals and the breadth of organ involvement.
Hand-arm vibration syndrome — currently flagged in contraindications and out-of-scope; distinct occupational condition with its own examination, compensation pathway, and trade-specific demographics.
Nailfold capillaroscopy — could warrant a short test-focused entry once primary-care availability widens.
Antinuclear antibody (ANA) testing — same; a high-yield screening test referenced across multiple connective-tissue-disease entries.
Smoking cessation — the behavioural tier's biggest lever; this entry currently mentions it without a back-link.

Separate-entry candidates. Systemic sclerosis and hand-arm vibration syndrome are the two clearest. Each is substantial enough to want full meta scoring and its own treatment ladder; flagged for the backlog.

Hard calls during the write.

How much systemic-sclerosis depth to put in stakes. Kept it concrete (digital ulcers, finger-skin thickening, ILD/PAH mentioned by implication) but deliberately did not detail the autoantibody panel (anti-centromere, anti-Scl-70, anti-RNA pol III) or the EULAR/ACR classification criteria — that belongs in the systemic sclerosis entry.
The α_2C-adrenoceptor name was cut from the mechanism section in favour of a plain-language gloss. The receptor mechanism is the cleanest piece of physiology in the field but the name itself is friend-test bait. The Herrick 2012 cite carries the precision.
Did not include a separate practicalities section despite real material (capillaroscopy availability, drug cost). The protocol section covers cost implicitly and the practicalities content didn't earn a standalone block.