An elevated heart rate is a common symptom when the body is fighting off an infection like a cold or the flu. For most adults, a resting heart rate between 60 and 100 beats per minute (bpm) is considered typical, but illness often pushes this number higher. While a temporary increase is a normal physiological response, a very high or sustained heart rate can be uncomfortable and concerning. This guide explains why this occurs and provides safe, actionable steps to manage an elevated heart rate from illness at home.
Why Sickness Causes an Elevated Heart Rate
The body increases heart function to meet the demands of fighting a pathogen. One primary driver is fever, which raises the body’s temperature to create an inhospitable environment for viruses or bacteria. This temperature rise increases the body’s metabolic rate, demanding more oxygen and nutrients to fuel the immune system. For every one degree Celsius (1.8°F) rise, the heart rate can increase by approximately 7 to 10 beats per minute.
Dehydration also contributes significantly to a faster heart rate during sickness. Vomiting, diarrhea, or increased sweating from a fever can lead to a reduction in blood volume. The heart must then pump faster to circulate the remaining, thicker blood and ensure oxygen reaches all tissues and organs.
Beyond fever and fluid loss, the body’s immune response triggers the release of inflammatory mediators and stress hormones. The “fight or flight” response is activated, flooding the system with catecholamines like adrenaline and cortisol. These hormones directly stimulate the heart muscle, causing it to beat with greater force and speed to combat the infection.
Effective Home Strategies for Lowering Your Heart Rate
The most direct way to reduce heart rate is to address the underlying physical stresses. Prioritizing rest is essential, as lying down or sitting quietly minimizes the demands placed on the heart that movement would create. Allowing the body to focus energy solely on recovery helps reduce the need for a fast heartbeat.
Rehydration helps restore blood volume and reduce the heart’s workload. Consuming water, clear broths, or electrolyte-rich drinks helps replace fluids and minerals lost through fever and other symptoms. This action directly counteracts the increased heart rate caused by dehydration, allowing the heart to pump a normal volume of blood more easily.
Temperature management is important for lowering the heart rate. Applying a cool compress to the forehead or neck, or wearing light, breathable clothing, can help gently reduce the body’s core temperature. By mitigating the fever response, the metabolic demand on the body decreases, which slows the heart rate.
Breathing techniques can promote a calming effect by engaging the vagus nerve, which helps shift the body from the sympathetic (stress) state to the parasympathetic (rest) state. The 4-7-8 technique involves inhaling quietly through the nose for a count of four, holding the breath for a count of seven, and then exhaling forcefully through the mouth for a count of eight. This extended exhale stimulates the vagus nerve and promotes relaxation.
A vagal maneuver, such as the diving reflex, involves splashing cold water onto your face or holding a bag of ice on your forehead for a few seconds. This sudden cold exposure stimulates the vagus nerve and may help temporarily slow an abnormally fast heart rhythm. More complex maneuvers, such as the Valsalva maneuver (straining), should only be performed after consulting with a healthcare professional.
Red Flags: When to Seek Professional Medical Care
While an elevated heart rate is common, certain symptoms require immediate medical evaluation. If your resting heart rate remains consistently high (typically over 100 to 120 beats per minute in adults) even after a fever has broken and you have rehydrated, you should contact a doctor.
Seek urgent care if the rapid heart rate is accompanied by symptoms such as the sudden onset of shortness of breath, chest pain or significant discomfort, or noticeable heart palpitations. Other warning signs include lightheadedness, dizziness, fainting, or any sudden confusion.
These symptoms suggest a potential lack of oxygen reaching the brain or an underlying cardiac issue. Do not attempt to manage these signs with home remedies; prioritize immediate medical attention for a proper diagnosis and treatment plan.