When you're sick, your body works harder to fight infection and that can put extra strain on your heart. Even common illnesses can affect your heart rate, rhythm and overall workload.
Most of the time, these changes go away after you recover from your illness. But for some symptoms, you may need further evaluation.
Ankur Gupta, MD, a cardiologist with Banner - University Medicine, explained more about how infection and inflammation can affect your heart.
How your body responds to infection
When your body notices an infection, your immune system jumps into action. That response triggers increases in inflammation, metabolism and your temperature. That means your organs, including your heart, may work harder for a short time.
Why your heart has to work harder when you're sick
Your heart helps move oxygen and nutrients to the rest of your body, and that job gets tougher when you're fighting an illness. Fever, inflammation and changes in your body’s fluids can all make your heart beat faster or work harder than usual to get blood to your body. Even people who don't have heart disease can feel this extra strain.
How infections can affect heart rate and rhythm
Tachycardia, or a faster heart rate, is one of the most common ways your body reacts to the fever, inflammation and stress of an illness. You may also notice palpitations, a racing feeling or a sense that your heart is skipping beats.
These changes usually improve as you recover, though they can sometimes linger for a little while after the illness has passed.
Can inflammation affect heart health long term?
“Short-term inflammation from most common illnesses is a normal part of fighting infection and usually doesn’t cause lasting harm,” Dr. Gupta said. “Most people recover from common illnesses with no heart complications, especially if they rest, stay hydrated and manage symptoms.”
But long-lasting inflammation can affect your blood vessels and may raise your risk of heart disease. The level of risk depends on your overall health, the type of illness and the inflammation’s severity.
When illness may affect the heart more seriously
“Even mild viral infections can sometimes trigger new or persistent heart rhythm problems that last for weeks or months after the illness,” Dr. Gupta said. “And certain respiratory infections can temporarily raise the risk of heart attack or stroke in the following weeks.”
Some illnesses put more stress on the heart than others, especially:
- Severe infections
- Repeat illnesses
- Illness when you already have conditions like heart disease, high blood pressure or diabetes
- Illness when you are older
- Severe flu or COVID-19
- Infections with a virus that causes myocarditis, which is inflammation of the heart muscle
Serious complications can include heart muscle inflammation or heart failure that gets worse.
Symptoms to watch during or after an illness
If something feels unusual for you, it's worth taking seriously. Watch for:
- Chest pain or pressure
- Shortness of breath, especially when you’re resting
- Dizziness or fainting
- Fatigue that doesn't improve
- Rapid or irregular heartbeat that doesn’t return to normal after you recover
- Swelling in the legs or ankles
When to seek medical care
Get medical care for:
- Heart-related symptoms that don't improve as your fever or other illness symptoms go away
- Fainting
- Symptoms that get worse instead of better
- Symptoms that feel new and unusual
- Illnesses when you have other health conditions
- Any concern you have about your heart after being sick
Get care right away for severe chest pain or trouble breathing.
How doctors evaluate heart symptoms after illness
A health care provider will usually start by asking about your medical history and symptoms. They may also do a physical exam and order tests like an ECG, blood work or imaging. In some cases, they may monitor your heart rhythm to see whether your symptoms are related to an infection or something else.
How to support your heart while recovering
Rest is important while your body heals, so it’s a good idea to return to your activities gradually. Staying hydrated can also help your body recover. If you still feel weak or tired, don't push through too quickly.
You can also help reduce the risk to your heart going forward. “If you have heart disease or risk factors, staying up to date on your flu and COVID vaccines and discussing any concerns with your doctor can help protect your heart during future illnesses,” Dr. Gupta said.
Bottom line
Infections and inflammation can temporarily stress your heart but most people recover without complications. If symptoms linger or feel unusual, getting checked can help make sure your heart is healthy.
If you have symptoms that don’t clear up after an illness or concerns about your heart, a Banner Health provider can evaluate your symptoms and help you recover.
FAQs about infection and heart health
Can being sick increase your heart rate?
Yes. Fever and inflammation can cause your heart to beat faster.
Is it normal to feel your heart racing during illness?
It can happen but it should improve as you recover.
Can infections cause long-term heart problems?
Most do not but some may require follow-up if symptoms persist.
When should you worry about heart symptoms after being sick?
If symptoms continue, worsen or feel unusual, you should seek care.
