Raynaud’s disease happens when small arteries in the fingers and toes overreact to cold or stress, temporarily cutting off blood flow. About 5% of the general population experiences it, with women affected slightly more often than men. The condition comes in two forms: primary Raynaud’s, which has no identifiable underlying cause, and secondary Raynaud’s, which develops alongside another disease or exposure.
How the Blood Vessels Overreact
Normally, your blood vessels narrow slightly when you’re cold to conserve heat. In Raynaud’s, this response is dramatically amplified. The small arteries feeding your fingers go into full spasm, completely blocking blood flow for minutes at a time. Your fingers turn white, then blue as oxygen runs out, then red and painful as blood rushes back in.
Two mechanisms drive this. The first is an overactive sympathetic nervous system, the same network responsible for your fight-or-flight response, sending too-strong signals telling blood vessels to clamp down. The second is a problem in the blood vessel walls themselves. The receptors that respond to those narrowing signals appear to be either more numerous or more sensitive than normal, so even a mild cold signal produces an exaggerated constriction. Both pathways likely contribute in most people, though the balance varies.
Primary Raynaud’s: No Clear Cause
Most people with Raynaud’s have the primary form, meaning no underlying disease is responsible. It typically starts between ages 15 and 30 and tends to run in families, though no single gene has been pinpointed. Episodes are uncomfortable but generally harmless. Fingers go white and numb, then throb as they rewarm, but permanent damage is rare.
The exact reason some people develop this hypersensitivity remains unclear. Researchers suspect a combination of genetic predisposition and environmental factors that together push the vascular response past its normal range. Being female is the strongest known risk factor.
Secondary Raynaud’s: Linked to Other Conditions
Secondary Raynaud’s develops because something else has already damaged or disrupted the blood vessels. It tends to appear later in life (often after age 30), produces more severe symptoms, and carries a higher risk of complications. The most common triggers fall into a few categories.
Autoimmune and Connective Tissue Diseases
Scleroderma is the condition most tightly linked to Raynaud’s. In scleroderma, the walls of small arteries thicken with scar tissue, narrowing the opening by 75% or more. When vasospasm hits on top of that structural damage, blood flow can stop almost entirely. Nearly all people with scleroderma experience Raynaud’s, and it’s often their very first symptom.
Lupus, rheumatoid arthritis, Sjögren’s disease, and inflammatory myositis also increase risk. So do certain thyroid disorders, clotting disorders, and carpal tunnel syndrome. In each case, the underlying disease either damages vessel walls, disrupts the signals controlling vessel tone, or both.
Medications
A surprisingly long list of medications can trigger Raynaud’s symptoms. Beta-blockers (commonly prescribed for high blood pressure and anxiety) are the best-known culprits. Migraine medications derived from ergot alkaloids are another classic trigger.
Beyond those, stimulant medications used for ADHD, certain antidepressants, some chemotherapy drugs, decongestants containing pseudoephedrine or phenylephrine, and several other classes of medication have all been linked to Raynaud’s episodes. If your symptoms started or worsened after beginning a new medication, that connection is worth exploring with your prescriber.
Occupational Vibration Exposure
Prolonged use of vibrating hand tools, such as jackhammers, grinders, chain saws, or drills, can cause a condition sometimes called vibration white finger. The cumulative trauma to blood vessels and nerves in the hands produces Raynaud’s symptoms that worsen over time. Severity depends on how long and how continuously you use the tools, and gripping the tool more tightly transmits more vibration into the hand. Workers in construction, forestry, and manufacturing are most commonly affected.
Cold and Stress as Triggers
Cold is the most obvious trigger, but it doesn’t have to be extreme. Reaching into a freezer, holding a cold drink, or walking into an air-conditioned room can be enough. The temperature drop doesn’t need to be dramatic; it just needs to cross the threshold where your particular vessels overreact.
Emotional stress triggers about a third of vasospastic attacks in people with primary Raynaud’s. These episodes occur with a racing heart and elevated stress levels but no drop in ambient temperature. In secondary Raynaud’s associated with scleroderma, cold alone provokes most attacks, and stress plays a smaller role.
When Raynaud’s Becomes Dangerous
Primary Raynaud’s rarely causes lasting harm. The episodes are unpleasant, but blood flow always returns and the tissue recovers fully. Secondary Raynaud’s is a different story, particularly in scleroderma.
When arteries are already narrowed by disease and a vasospasm shuts off the remaining trickle of blood, tissue can actually starve. Digital ulcers, painful open sores on the fingertips, develop in 30 to 50% of scleroderma patients. Of those who develop persistent ulcers, about 30% experience irreversible tissue loss. Amputation of one or more fingers occurs in roughly 20% of scleroderma patients, with about 9% losing multiple digits.
This progression from vasospasm to permanent damage is what separates the two forms of the condition. In secondary Raynaud’s, the vasospasm acts on blood vessels that are already structurally compromised. Injured vessel linings malfunction, tiny clots form more easily, and each episode compounds the damage from the last. That escalation is why secondary Raynaud’s requires closer monitoring and more aggressive management than the primary form.
What Makes Some People More Susceptible
Several factors increase the likelihood of developing Raynaud’s or having more frequent episodes. Living in a cold climate is the most straightforward: more cold exposure means more opportunities for vasospasm. Smoking narrows blood vessels and damages their linings, worsening symptoms regardless of which form you have. Family history matters, particularly for primary Raynaud’s, suggesting a genetic component even if the specific genes haven’t been identified.
For secondary Raynaud’s, the biggest predictor is the severity of the underlying disease. Someone with mild lupus may have occasional finger color changes, while someone with progressive scleroderma faces a much higher risk of tissue damage. The Raynaud’s itself is essentially a barometer of how much vascular disease is present underneath.