Does blood pressure increase when fighting a virus?

Blood Pressure Changes During Viral Infections

Blood pressure may increase during viral infections due to upregulation of the ACE/Angiotensin II pathway, which occurs to maintain adequate organ perfusion during acute illness. 1

Physiological Mechanisms of BP Changes During Viral Infections

• During acute viral infections, the ACE/Angiotensin II pathway is upregulated to maintain adequate organ perfusion, which can lead to increased vasoconstriction and blood pressure 1
• If this upregulation occurs without a compensatory increase in the ACE2/Angiotensin-(1-7) pathway, deleterious hypertension can potentially develop 1
• The inflammatory response to viral infection can affect vascular tone, fluid status, and kidney function, all of which influence blood pressure regulation 1
• Fever, which commonly accompanies viral infections, can also impact blood pressure through effects on vasodilation and cardiac output 1

Evidence from COVID-19 Research

COVID-19 has provided significant insights into how viral infections may affect blood pressure:

• Initial reports suggest that blood pressure at presentation might be higher in patients who develop more severe COVID-19, independent of baseline hypertension 1
• SARS-CoV-2 infection can potentially lead to dysregulation of the renin-angiotensin system (RAS) through binding to ACE2 receptors 1
• Loss of pulmonary endothelial ACE2 due to viral binding can lead to increased circulating Angiotensin II, promoting vasoconstriction and sodium/water retention 1
• Recent studies have shown that COVID-19 is associated with a 65% increased risk of new-onset hypertension compared to controls 2

Short-term vs. Long-term Effects

The relationship between viral infections and blood pressure appears to vary over time:

• During active infection, some patients may experience elevated blood pressure due to RAS dysregulation 1, 3
• A study of 153 COVID-19 patients found significantly higher systolic and diastolic blood pressure in the post-COVID period compared to admission values 3
• Conversely, some research has shown blood pressure reductions during pandemic lockdown periods, possibly due to lifestyle changes 4
• Long-term follow-up studies indicate that even after non-severe COVID-19, individuals may have higher diastolic blood pressure (+4.7 mmHg) compared to matched controls 5

Clinical Implications

• Monitoring blood pressure during and after viral infections may be important, particularly in patients with pre-existing cardiovascular risk factors 1, 2
• The interaction between viral infections and blood pressure regulation is complex and may involve multiple pathways including inflammation, endothelial dysfunction, and RAS dysregulation 1, 6
• Patients with controlled hypertension may paradoxically have higher risk of adverse outcomes with COVID-19, possibly due to more advanced atherosclerosis and target organ damage 7
• The effects of viral infections on blood pressure may persist beyond the acute phase, as evidenced by increased rates of new-onset hypertension following COVID-19 2, 5

Potential Pitfalls in Assessment

• Blood pressure measurements during acute illness may be affected by anxiety, pain, and medications used to treat the viral infection 1
• Multiple factors influence blood pressure during acute illness, including fever, inflammatory response, fluid status, and kidney function 1
• Distinguishing between transient blood pressure elevations during infection versus new-onset hypertension requires follow-up measurements after recovery 2, 3
• Home blood pressure monitoring may provide more accurate assessment of true blood pressure changes during viral infections compared to clinic measurements 4