Shingles, also known as herpes zoster, is a viral infection caused by the reactivation of the varicella-zoster virus, the same virus responsible for chickenpox. After chickenpox, the virus remains dormant in nerve cells, reactivating later in life as a painful rash with blisters on one side of the body or face.
The Connection to Blood Clots
Research indicates a shingles infection can increase the risk of blood clots, including deep vein thrombosis (DVT), pulmonary embolism (PE), stroke, and heart attack. This elevated risk is generally temporary, peaking in the weeks and months following the outbreak, but can persist for up to a year.
Individuals who have had shingles may experience a 30% to 40% higher risk of a subsequent stroke or heart attack. This highlights the viral infection’s broader impact on the cardiovascular system, extending beyond the acute rash phase.
How Shingles May Increase Clot Risk
The body’s response to the varicella-zoster virus during a shingles outbreak creates conditions favorable for blood clot formation. One mechanism involves systemic inflammation, where the viral infection triggers a widespread inflammatory response leading to a pro-thrombotic state.
Recent research points to the role of exosomes. These tiny cellular sacs, released by cells during infection, carry prothrombotic and proinflammatory proteins. Circulating in the bloodstream, these substances contribute to increased clotting potential even after the rash heals.
The virus can also directly affect blood vessels, leading to vasculopathy. This involves damage to the endothelium, the inner lining of blood vessels, which can initiate clot formation and contribute to pathological changes. Inflammation also increases platelet activation and aggregation, making platelets more sticky and prone to clumping.
Identifying Clot Symptoms and Individual Risk
Recognizing blood clot symptoms is important for timely medical intervention. DVT may present as swelling, pain, warmth, or discoloration in the affected limb. PE can cause sudden shortness of breath, chest pain, rapid heart rate, lightheadedness, or coughing up blood.
A stroke might manifest as sudden weakness or numbness on one side of the body, difficulty speaking, dizziness, or severe headaches. Heart attack symptoms involve chest pain or discomfort that can spread to the arms, back, neck, jaw, or stomach, often with shortness of breath, nausea, or lightheadedness. Immediate medical attention is necessary if any of these symptoms appear.
Factors increasing an individual’s risk of blood clots after shingles include older age, severity of infection, and rash on the face (zoster ophthalmicus) due to proximity to the brain. Pre-existing conditions like cardiovascular disease or a history of blood clots also increase risk.
Prevention and Seeking Medical Guidance
Preventing shingles and reducing associated blood clot risk is primarily achieved through vaccination. The shingles vaccine is highly effective, lowering the inflammatory burden that contributes to cardiovascular complications. Studies show vaccinated individuals have a reduced risk of cardiovascular events, including stroke and heart attack.
Individuals who develop shingles, especially those with underlying risk factors for blood clots, should consult their healthcare provider promptly. Early medical evaluation can help manage the infection and assess potential cardiovascular risks. Managing existing health conditions, such as high blood pressure or diabetes, contributes to overall vascular health and can help mitigate blood clot formation. Seeking timely medical advice for any suspected blood clot symptoms is important for preventing serious complications.