Raynaud's Phenomenon
Raynaud's is a common condition where blood vessels in the fingers and toes overreact to cold or stress, causing episodes of colour change: white (blanching — vasospasm) → blue (cyanosis — deoxygenation) → red (reactive hyperaemia on rewarming). Primary Raynaud's is benign and common, especially in young women. Secondary Raynaud's is associated with autoimmune diseases like scleroderma, lupus, and rheumatoid arthritis and requires investigation.
Causes and Blood Tests
| Cause | Key Test | Clinical Features |
|---|---|---|
| Hypothyroidism | TSH | Cold intolerance, fatigue, weight gain, dry skin alongside cold extremities |
| Iron deficiency / Anaemia | Ferritin, Haemoglobin, CBC | Pallor, fatigue, breathlessness — reduced blood flow to extremities |
| Secondary Raynaud's (autoimmune) | ANA (antinuclear antibody), RF (rheumatoid factor), anti-SCL-70 (scleroderma) | Severe colour changes, digital ulcers, joint pain — suggests connective tissue disease |
| Peripheral arterial disease | Ankle-Brachial Index (ABI), lipid profile | Pain on walking (claudication), weak pulses — especially in smokers, diabetics |
| Diabetes (peripheral neuropathy) | HbA1c, fasting glucose | Coldness with numbness, burning, tingling — peripheral neuropathy pattern |
| Vitamin B12 deficiency | Serum B12, MCV | Cold hands with numbness, paraesthesia, fatigue |
Blood Tests to Request
- TSH — Screen for hypothyroidism
- CBC, Haemoglobin, Ferritin — Check for anaemia and iron deficiency
- Fasting glucose / HbA1c — Exclude diabetes
- ANA (Antinuclear Antibody) — If Raynaud's is severe or digital ulcers present; screens for autoimmune disease
- RF (Rheumatoid Factor) — If joint symptoms coexist
- Vitamin B12 — If numbness or tingling accompanies cold hands
Lifestyle Tips for Cold Extremities
- Layer clothing, especially gloves and socks — keep core body warm
- Warm drinks and warm water can help relieve acute episodes
- Avoid smoking — nicotine causes severe vasoconstriction
- Limit caffeine, which can worsen vasoconstriction
- Chemical hand warmers for Raynaud's attacks in cold weather
- For severe Raynaud's: calcium channel blockers (nifedipine) may be prescribed
Questions to Ask Your Doctor
- Do I have Raynaud's, and if so, is it primary or secondary?
- Should I be tested for thyroid disease and anaemia?
- Do I need autoimmune blood tests like ANA?
- Is there any medication that could help the cold episodes?
- Should I see a rheumatologist if autoimmune tests are positive?
Medical Disclaimer: This information is for educational purposes only. Cold hands and feet can be normal or may indicate an underlying medical condition requiring evaluation.