When unwell, your body undergoes changes, and a common, temporary effect can be a rise in blood pressure. This physiological response is how your system reacts to stressors like illness, offering insight into your health during sickness.
The Body’s Response to Illness
When illness takes hold, your immune system activates to combat invaders. This triggers the release of stress hormones like adrenaline and cortisol. These hormones are part of the “fight or flight” response, causing your heart to beat faster and blood vessels to narrow, which temporarily elevates blood pressure.
Inflammation, the body’s natural response to illness, is another factor. During infection, inflammatory mediators are released. Persistent or severe inflammation can damage blood vessel linings, making them less flexible and narrower. This increases resistance to blood flow, raising blood pressure.
Pain can increase blood pressure by activating the sympathetic nervous system and releasing stress hormones. Fever, a common symptom, causes the heart to beat faster to circulate blood more efficiently. This increased cardiac output can lead to blood pressure fluctuations.
Dehydration, often from fever, vomiting, or diarrhea, also influences blood pressure. When fluids are insufficient, blood volume decreases, and blood thickens, making the heart work harder. Dehydration also prompts the release of hormones like vasopressin, which constrict blood vessels and cause kidneys to retain water, increasing blood pressure.
Common Illnesses and Their Blood Pressure Impact
Various common illnesses can temporarily increase blood pressure. Respiratory infections like the common cold, influenza, and pneumonia often trigger inflammation and stress hormone release. This can elevate blood pressure.
Even less severe conditions, such as a cold, can prompt the heart to work harder, leading to a temporary blood pressure rise. Infections like urinary tract infections (UTIs) can also cause inflammation and stress responses. Severe infections like sepsis can lead to significant blood pressure spikes.
Certain over-the-counter medications for cold and flu symptoms can impact blood pressure. Decongestants can narrow blood vessels, increasing blood pressure. Pain relievers and anti-inflammatory medications can cause water retention, leading to higher readings.
When to Seek Medical Advice
While a temporary blood pressure rise during illness is often normal, some situations warrant medical attention. If readings are consistently high, particularly above 180/120 mmHg, it is a hypertensive crisis requiring immediate medical evaluation, especially with concerning symptoms.
Emergency symptoms with very high blood pressure include severe chest pain, shortness of breath, headache, blurred vision, confusion, nausea, vomiting, or signs of stroke like numbness or weakness. Seek emergency medical help if you experience any of these. For individuals with pre-existing conditions like chronic hypertension, diabetes, or heart disease, monitoring blood pressure during illness is important.
If you get a very high reading at home but have no other symptoms, relax and recheck your blood pressure. If it remains significantly high, contact your healthcare provider for guidance. They can advise on medication adjustments or if an in-person visit is necessary.