This health alert highlights an important fact: Stroke risk is not limited to people with high blood pressure or diabetes. Certain viral infections can also temporarily increase the risk of a stroke.
Although most people recover from common viral infections without serious complications, some infections can affect blood vessels, increase inflammation and disturb normal blood clotting.
Let’s understand everything step by step.
1. What is a stroke?
A stroke occurs when the blood supply to a part of the brain is interrupted or when a blood vessel in the brain bursts.
When brain cells do not receive enough oxygen and nutrients, they begin to get damaged within minutes.
There are two main types:
- Ischemic stroke: A blood clot blocks blood flow to the brain. This is the most common type.
- Hemorrhagic stroke: A blood vessel bursts and causes bleeding inside or around the brain.
2. How can a viral infection cause a stroke?
This is the most important part of the health alert.
When a virus enters the body, the immune system becomes active to fight the infection. Sometimes this response can affect the cardiovascular system.
There are four possible ways this can happen:
1. Increased inflammation: The immune system releases inflammatory chemicals to fight the virus. Excessive inflammation can affect the inner lining of blood vessels.
2. Blood clot formation: Some infections can make blood more likely to clot. If a clot blocks an artery supplying the brain, it can cause an ischemic stroke.
3. Damage to blood vessels: Certain viruses can directly or indirectly affect blood vessel walls, causing inflammation and circulation problems.
4. Heart complications: Some viral infections can affect the heart and its rhythm. In certain cases, blood clots may form in the heart and travel to the brain.
Research published in 2025 found that influenza was associated with approximately 4.7 times higher stroke risk during the 28 days following infection. This is a relative increase in risk, not a prediction that someone with flu will have a stroke. PubMed+2
3. Which viral infections may increase stroke risk?
Some infections associated with an increased risk include:
- Influenza (Flu): Can trigger inflammation and increase blood-clotting activity.
- COVID-19: Can affect blood vessels, inflammation and the body’s clotting system.
- Shingles: Caused by the varicella-zoster virus, which can sometimes affect blood vessels supplying the brain.
- HIV: Long-term infection can contribute to inflammation and cardiovascular complications.
- Hepatitis C: Has been associated with an increased risk of cardiovascular problems, including stroke.
Remember: having one of these infections does not mean a person will definitely experience a stroke. American Heart Association+1
4. Who should be extra careful?
People who should pay particular attention to their health include:
- People with high blood pressure.
- People living with diabetes.
- Individuals with high cholesterol.
- People with existing heart disease.
- Older adults.
- People who smoke.
- Individuals with a previous stroke or mini-stroke.
- People with weakened immune systems.
Having multiple risk factors can increase overall risk. CDC+1
5. How can you protect yourself?
Important preventive measures
1. Stay hydrated: Drink enough water, especially during fever, vomiting or diarrhoea, unless your doctor has advised fluid restriction.
2. Get recommended vaccinations: Flu and COVID-19 vaccinations can help reduce the risk of severe infections.
3. Eat a balanced diet: Include fruits, vegetables, whole grains, pulses, nuts and healthy fats.
4. Exercise regularly: Aim for around 150 minutes of moderate physical activity per week, if medically suitable.
5. Monitor blood pressure: Check your BP regularly, even if you feel healthy.
6. Control diabetes and cholesterol: Follow your doctor’s advice and take prescribed medicines regularly.
7. Avoid smoking: Smoking damages blood vessels and increases stroke risk.American Heart Association+2
6. What are the warning signs of a stroke?
Medical emergency
Remember the B.E. F.A.S.T. rule:
- B – Balance: Sudden loss of balance or difficulty walking.
- E – Eyes: Sudden blurred vision or loss of vision.
- F – Face: One side of the face suddenly droops.
- A – Arms: Sudden weakness or numbness in one arm.
- S – Speech: Difficulty speaking or slurred speech.
- T – Time: Immediately seek emergency medical help.
If you notice even one of these symptoms, call emergency services (112 in India) or get emergency medical care immediately. Do not wait for symptoms to disappear. Even temporary symptoms can indicate a mini-stroke (TIA). CDC+1
7. Can a stroke be prevented?
Many strokes can be prevented by managing health conditions and maintaining healthy habits.
- Maintain a healthy weight.
- Keep blood pressure under control.
- Avoid excessive salt and processed foods.
- Get enough sleep.
- Stay physically active.
- Treat infections appropriately.
- Attend regular health check-ups.
8. Important things to remember
- A viral infection does not automatically cause a stroke.
- Stroke can happen even in younger people.
- High blood pressure remains one of the major stroke risk factors.
- The risk may temporarily increase after certain infections, particularly influenza and COVID-19.
- Early recognition and emergency treatment can save lives.
Final takeaway: Never ignore persistent or severe illness, and never ignore sudden neurological symptoms. Taking care of your heart, blood vessels and overall health is also essential for protecting your brain.
Reliable references for further reading:
- American Heart Association – Viral infections and cardiovascular risks
- CDC – Stroke warning signs
- WHO – Stroke facts and prevention
