The flu, a common respiratory illness caused by influenza viruses, can significantly impact overall health. It typically presents with symptoms like fever, body aches, and respiratory issues. Blood pressure, the force of blood against artery walls, is a fundamental measure of cardiovascular health. While generally stable, various factors can cause it to fluctuate.
How Flu Affects Blood Pressure
The flu can cause a temporary increase in blood pressure due to several physiological responses. The body’s immune system activates in response to the viral infection, leading to systemic inflammation. This inflammation can cause blood vessels to constrict, a process known as vasoconstriction, which directly raises blood pressure by increasing resistance to blood flow.
The stress of fighting off an infection triggers the sympathetic nervous system, often referred to as the “fight or flight” response. This activation leads to the release of hormones like adrenaline and noradrenaline, which cause the heart to beat faster and blood vessels to narrow, contributing to elevated blood pressure. A fever, a common flu symptom, also contributes by making the heart work harder, leading to an increased heart rate and higher blood pressure.
Dehydration, a complication of the flu, can also influence blood pressure. While severe dehydration can cause blood pressure to drop, the body’s attempt to correct this can lead to an increase. Certain over-the-counter flu medications, such as decongestants containing pseudoephedrine or phenylephrine, can constrict blood vessels and increase blood pressure and heart rate. These effects are temporary and resolve as the flu infection clears.
Individuals at Higher Risk
While the flu can temporarily raise blood pressure in healthy individuals, certain populations face a greater risk of significant changes. Individuals with pre-existing conditions such as hypertension, heart disease, kidney disease, and diabetes are particularly vulnerable. For instance, people with heart disease are at least six times more likely to experience a heart attack after a flu infection.
The elderly also face increased risks due to their compromised immune systems and higher likelihood of having underlying health issues. Pregnancy is another group at higher risk for flu complications, including blood pressure fluctuations. These groups are more susceptible because their bodies may struggle to cope with the added stress and inflammatory response caused by the flu, potentially leading to more severe cardiovascular complications.
Managing Blood Pressure During Illness
Managing blood pressure during a flu infection involves several steps. Staying well-hydrated is important, as dehydration can contribute to blood pressure fluctuations; consume plenty of clear fluids such as water, juice, or broth. Adequate rest is also recommended, as it allows the body to conserve energy and focus on fighting the infection.
When considering over-the-counter medications for flu symptoms, check labels carefully. Decongestants like pseudoephedrine and phenylephrine can raise blood pressure and should be avoided by individuals with hypertension. Acetaminophen or aspirin can be used for fever and body aches, but nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen or naproxen can also elevate blood pressure and should be used with caution. Saline nasal sprays and humidifiers can help relieve congestion without affecting blood pressure.
Seek medical attention if your blood pressure remains elevated for a sustained period or if you have concerning symptoms. Contact a healthcare professional if your systolic blood pressure (the top number) is consistently around 150 mm Hg or higher. Emergency care is warranted for a hypertensive crisis, indicated by blood pressure readings of 180/120 mm Hg or higher, especially with symptoms like chest pain, shortness of breath, severe headache, vision changes, numbness, weakness, or difficulty speaking.