Infections can significantly influence various bodily functions, and the cardiovascular system is no exception. When your body encounters an invading pathogen, such as bacteria or viruses, it initiates a complex defensive response. This immune activation can lead to temporary adjustments in how your blood circulates, which may in turn affect blood pressure readings.
Understanding Blood Pressure Changes During Infection
Infections can lead to fluctuations in blood pressure, causing both temporary increases and potentially dangerous decreases. When an infection takes hold, the body’s immune system launches a response that can lead to inflammation. This inflammatory process can cause blood vessels to narrow, making it harder for blood to flow and potentially raising blood pressure temporarily. The heart may also work harder to pump blood to infected tissues, further contributing to this elevation.
Conversely, severe infections, particularly those progressing to sepsis, can cause a significant drop in blood pressure, known as hypotension. Sepsis is a life-threatening condition where the body’s response to infection damages its own tissues and organs. This decrease in blood pressure occurs due to widespread widening of blood vessels, a process called vasodilation, and increased permeability of these vessels. Fluid can leak from the blood vessels into surrounding tissues, reducing the overall blood volume and leading to a drop in pressure.
The Body’s Underlying Responses
The immune system plays a central role in how infections influence blood pressure. When an infection occurs, the body releases inflammatory mediators like cytokines and histamines. These signaling molecules are part of the immune response, but they can also affect the walls of blood vessels, causing them to either constrict or become less flexible, which can contribute to increased blood pressure.
In severe infections, widespread inflammation can cause blood vessels to widen significantly, reducing resistance to blood flow and causing blood pressure to fall. Simultaneously, vessel walls can become “leaky,” allowing fluid to escape into surrounding tissues. This fluid shift decreases the effective blood volume, further contributing to a dangerous drop in blood pressure.
Beyond these direct vascular effects, severe infections can also strain organs like the heart and kidneys. The heart may struggle to pump enough blood to meet the body’s demands, while kidney dysfunction can disrupt fluid and electrolyte balance, both of which contribute to blood pressure dysregulation. The body’s stress response also plays a part, as infections can stimulate the release of hormones like cortisol and adrenaline from the adrenal glands. These hormones can temporarily increase heart rate and blood pressure as part of the body’s fight-or-flight mechanism.
When to Seek Medical Care
If you experience symptoms like dizziness, lightheadedness, or fainting alongside an infection, it could indicate dangerously low blood pressure. Persistent very high blood pressure readings during an infection, particularly if accompanied by other concerning symptoms, should also prompt a medical consultation. These changes may signal that your body is struggling to manage the infection.
Other symptoms that may accompany a severe infection and require immediate medical evaluation include difficulty breathing, confusion or disorientation, and a rapid heart rate. A fever that does not respond to typical over-the-counter medications is also a warning sign. Timely diagnosis and treatment are particularly important for conditions like sepsis, where rapid medical intervention can significantly improve outcomes.