How Inflammation Impacts the Heart

When you experience an injury or infection, your body naturally defends against the germs or toxins and works to heal the affected area, creating inflammation in the process.

Short-term inflammation is normal and helps you recover. However, when inflammation lasts for months or years, it can harm your organs, especially your heart.

Inflammation happens when your immune system reacts to a trigger — such as infection, injury or stress — to protect your body. Your body sends inflammatory cells and proteins called cytokines to the area that needs healing.

There are two types of inflammation:

• Acute inflammation is short-term, lasting hours or days. You may notice swelling, redness, warmth and pain at the site.
• Chronic inflammation happens when inflammation persists in healthy tissue.

“Chronic inflammation often occurs in response to common medical conditions such as obesity, diabetes, chronic kidney disease and chronic lung disease,” says Sanjiv J. Shah, MD, a cardiologist at Northwestern Medicine and professor at Northwestern University Feinberg School of Medicine. “It can also be triggered by autoimmune diseases.”

Symptoms of chronic inflammation can improve or get worse over time. They may include:

• Pain, especially abdominal or chest
• Fever
• Fatigue or trouble sleeping
• Joint pain or stiffness
• Mouth sores
• Rash
• Mood changes, such as depression or anxiety
• Gastrointestinal issues, including diarrhea, constipation or acid reflux
• Weight gain or weight loss
• Frequent infections

How Chronic Inflammation Affects the Heart

“Our research shows that chronic inflammation is putting a strain on the heart,” Dr. Shah says.
 “When the heart muscle becomes inflamed, it can stiffen the heart or weaken it and impair its ability to pump blood effectively. This can lead to an inability to keep up with the demands of the body.”

These impairments can lead to several heart conditions, including:

• Heart failure: When the heart can’t fill or pump blood as well as it should.
• Heart attack: Blood flow to the heart is blocked, causing damage to the heart muscle.
• Atherosclerosis: Plaque buildup in the arteries reduces blood flow.
• Arrhythmia: Irregular heart rhythms.

Chronic inflammation can raise pressure in the heart and increase the risk of fluid retention and blood clots.

Top Causes of Chronic Inflammation

Some medical conditions may cause the body to remain in a constant state of inflammation, straining the heart and increasing the risk of heart disease, which is the leading cause of death in the United States. Contributing risk factors include:

• High blood pressure
• Obesity
• Type 2 diabetes or prediabetes
• Chronic kidney disease
• High cholesterol

Inflammation of the heart can also occur due to infections, such as viral, bacterial or fungal infections. For example, the virus that causes COVID-19 can directly infect the heart muscle cells and damage blood vessels in the heart, causing inflammation. 

Similarly, autoimmune diseases like rheumatoid arthritis or lupus, where the immune system mistakenly attacks the body's own tissues, can trigger an inflammatory response in the heart. 

Smoking, exposure to toxins, chest injury and certain medications also play a role.

Symptoms to Watch For

Inflammation of the heart can be hard to detect at first. Warning signs may include:

• Chest pain or pressure
• Shortness of breath
• Irregular heartbeat
• Swelling in the legs or feet
• Lightheadedness or fainting
• Fatigue
• Flu-like symptoms, such as fever and body aches

If you notice any of these symptoms, especially after a recent illness or infection, seek medical attention immediately.

How to Treat Inflammation

Treatment depends on the cause and severity of the inflammation. Medications, such as anti-inflammatories and immunosuppressants, may be prescribed to reduce inflammation and manage symptoms.

In severe cases, hospitalization and more intensive treatments, such as intravenous (IV) medications or surgery, may be necessary.

Along with exercise and a heart-healthy diet, medications commonly used to protect the heart can also help reduce inflammation. Statins can lower cholesterol and other fat in the blood, decreasing the chance of clogged arteries. They can also reduce inflammation in the body.

Weight loss medications known as GLP-1 receptor agonists (incretins), such as semaglutide (Ozempic®, Wegovy®) and tirzepatide (Mounjauro®, Zepbound®), also dramatically reduce inflammation, says Dr. Shah.

Other medications include:

• ACE inhibitors or angiotensin receptor blockers: Lower blood pressure and ease the strain on the heart
• Antiplatelet medications: Help prevent blood clots
• Beta blockers: Lower blood pressure and slow heart rate
• Blood sugar and fluid balance medications (SGLT2 inhibitors): Improve your body’s metabolism and reduce fluid overload

Your doctor or cardiologist can help you determine which medications are right for your condition. Your care team will also monitor your blood pressure and test your cholesterol and blood sugar (A1C) regularly.

Can You Prevent Inflammation?

“Yes, you can prevent inflammation and maintain a healthy heart,” says Dr. Shah. “It starts with taking care of your heart and immune system and managing underlying health conditions.”

Here’s how to reduce the risk of inflammation:

• Eat a balanced diet rich in fruits, vegetables, whole grains, lean proteins and healthy fats. The DASH eating plan and the Mediterranean diet are examples of heart-healthy eating.
• Skip fried or processed foods as well as those high in saturated fat and sugar.
• Exercise regularly to improve blood flow. Walking at least 6,000 steps a day has been linked to lower cardiovascular risk.
• Avoid smoking.
• Limit or avoid alcohol.
• Manage stress through mindfulness, therapy or relaxation techniques.
• Get regular checkups to monitor blood pressure, cholesterol and blood sugar.

The Future of Heart Care

Northwestern Medicine Bluhm Cardiovascular Institute and Feinberg Cardiovascular & Renal Research Institute are pioneering treatments that target inflammation to improve heart health.

In a study, scientists examined heart tissue and found that specific immune cells can enter the heart and remain active there during chronic inflammation. Over time, this activity can damage heart tissue and interfere with the heart’s function: a condition known as heart failure with preserved ejection fraction (HFpEF).

HFpEF happens when the ventricles of the heart do not relax as they should. The heart’s stiffness limits the amount of blood filling into the heart, which causes fluid to build up in the lungs and the body.

“We’ve known for years that inflammation plays an important role in this kind of heart failure,” says Mallory Filipp, PhD, a postdoctoral fellow and first author of the HFpEF study. “But the mechanisms and what exactly was happening were not well understood. So, we started by trying to figure out what immune cell subsets we could see within the heart. Now we’re coming back full circle and asking, ‘Once these cells are in the heart, what are they doing that’s causing cardiac damage?’”

This study adds to ongoing HFpEF research at Northwestern Medicine led by Dr. Shah’s HFpEF program, where he and his team are studying how to address this historically difficult-to-treat condition. Today, they are making strides in observing how heart cells can be treated to reduce inflammation and improve heart function.

Take the Next Step

Chronic inflammation often develops quietly, long before symptoms appear. Identifying risk factors early and addressing them through medical care and lifestyle changes can help protect the heart over time.

If you’re concerned about inflammation or your heart health, talk to your primary care provider or a cardiologist. Early detection is essential in accessing the care you need.