Raynaud's Phenomenon:
Causes, Symptoms, and What to Do

Raynaud's phenomenon (also called Raynaud's disease or Raynaud's syndrome) is a condition in which the small blood vessels in the fingers, and sometimes toes, ears, or nose, overreact to cold or emotional stress, causing them to temporarily spasm and restrict blood flow.

The result is the characteristic colour change: white (pallor from lack of blood flow), then blue (cyanosis from deoxygenated blood), then red (as blood rushes back and the tissue re-perfuses). Not everyone goes through all three phases, many people skip one or alternate between them.

Primary vs Secondary Raynaud's

The distinction between primary and secondary Raynaud's is clinically important because the management and implications differ significantly.

Primary Raynaud's

Also called Raynaud's disease. Occurs on its own, without any underlying condition. It's common, affects about 3–5% of the general population, predominantly young women. Features that suggest primary Raynaud's:

• Onset in adolescence or early adulthood
• Symptoms are symmetric and affect multiple fingers
• No tissue damage, ulcers, or scarring
• Normal blood tests (no autoantibodies, normal inflammatory markers)
• No other symptoms suggesting connective tissue disease

Primary Raynaud's is generally benign. It can be uncomfortable and affect quality of life, but it doesn't damage organs or tissues and doesn't usually progress to secondary disease.

Secondary Raynaud's

Also called Raynaud's syndrome. Occurs as part of an underlying disease, most commonly an autoimmune connective tissue disease. Secondary Raynaud's tends to be more severe and may cause complications like digital ulcers (painful sores on the fingertips). Features suggesting secondary Raynaud's:

• Onset after age 30
• Asymmetric or involving only 1–2 fingers
• Severe attacks causing prolonged colour change
• Digital ulcers or pitting (small scars on fingertips)
• Abnormal nail fold capillaroscopy (dilated or absent capillaries at the nail fold, a key examination finding)
• Positive autoantibodies (ANA, anti-Scl-70, anti-centromere)
• Other symptoms of connective tissue disease

Which Autoimmune Diseases Cause Secondary Raynaud's?

Raynaud's is extremely common in several autoimmune conditions:

• Systemic sclerosis (scleroderma), virtually all patients have Raynaud's; it's often the very first symptom, preceding skin and organ involvement by years
• Mixed connective tissue disease (MCTD), Raynaud's is a near-universal feature
• Lupus (SLE), about 30–40% of lupus patients have Raynaud's
• Sjögren's syndrome, about 15–30%
• Rheumatoid arthritis, less common but recognised
• Inflammatory myositis, particularly dermatomyositis

Non-Autoimmune Causes

Raynaud's can also occur with:

• Vibration-induced (from using vibrating tools)
• Certain medications (beta blockers, some chemotherapy, ergot-derived drugs)
• Thoracic outlet syndrome
• Atherosclerosis
• Hypothyroidism

When Should I See a Doctor?

If you have Raynaud's, you should be evaluated if any of the following apply:

• You're over 30 and symptoms are new
• Attacks are severe, prolonged, or painful
• You have digital ulcers or fingertip pitting
• You have other symptoms, joint pain, fatigue, dry eyes/mouth, skin tightening
• Attacks involve only one or two fingers (asymmetric)
• Family history of autoimmune disease

What Tests Will a Doctor Do?

• ANA and ENA panel, screening for autoimmune connective tissue disease
• Anti-centromere antibody, specific for limited systemic sclerosis
• Anti-Scl-70, associated with diffuse systemic sclerosis
• Nail fold capillaroscopy, examination of the tiny blood vessels at the base of the fingernails under magnification; abnormal patterns strongly suggest secondary Raynaud's
• Full blood count, inflammatory markers, thyroid function