Myocarditis and pericarditis are conditions that involve heart inflammation. Myocarditis affects the heart muscle itself, while pericarditis impacts the pericardium — the layer of tissue that surrounds the heart.

Viral infections are the most common cause of myocarditis and pericarditis globally. Since the inflammation from one part of your heart may spread to surrounding tissue, these cardiac diseases often manifest at the same time. This is called myopericarditis or perimyocarditis.

An estimated 2% of the global population has myocarditis, which is easier to detect and diagnose than pericarditis. Scientists think the actual number of people with either myocarditis or pericarditis is likely much higher than estimates suggest.

You may have read about them in the news in recent years since they’re among the most common — although still rare — complications associated with SARS-CoV-2 and COVID-19. The diseases have also rarely been linked to vaccines, including COVID mRNA varieties.

However, these conditions are highly treatable. Here’s more about their causes, symptoms, and treatment.

Common causes of myocarditis include:

  • viral or bacterial infections
  • autoimmune conditions
  • allergic or hypersensitivity reactions to medication
  • drug toxicity
  • parasites

Common causes of pericarditis include:

  • viral, bacterial, fungal or protozoal infections
  • kidney failure
  • rheumatologic diseases like arthritis
  • inflammatory-causing medications
  • post-pericardiotomy syndrome
  • high dose radiation used for cancer treatment
  • Kawasaki disease

Other causes of both conditions include:

  • vaccinations (including rarely after COVID-19 mRNA vaccines)
  • other inflammatory conditions (like inflammatory bowel disease)
  • chest cavity trauma

Symptoms of myocarditis and pericarditis are typically very similar and may include:

Myocarditis vs. pericarditis: Which is worse?

Although both conditions may (rarely) be life threatening, scientists say myocarditis is associated with more severe consequences.

Myocarditis complications can range from mild chest pain to cardiac shock.

Meanwhile, pericarditis is associated with dilated cardiomyopathy (enlargement of the left heart ventricle) and, very rarely, heart failure.

Treatment for myocarditis or pericarditis depends on the severity of the disease. Most of the time, the conditions are highly treatable, and a full recovery is likely.

In mild cases, myocarditis or pericarditis may even resolve without intervention.

In more severe cases, treatment may include:

  • Taking medication: For pericarditis, the first line of treatment is often nonsteroidal anti-inflammatory drugs (NSAIDs). Treatment may also include an intravenous (IV) medication called immunoglobin, which helps combat bacteria, viruses, and fungi. In the case of systolic heart failure, treatment may include beta-blockers, diuretics, or ACE inhibitors. Corticosteroids or antibiotics may also be prescribed.
  • Avoiding certain medications:For myocarditis, doctors do not prescribe NSAIDs. They may recommend you avoid immunosuppressant drugs and NSAIDs like ibuprofen.
  • Lifestyle changes:Immediately after diagnosis, doctors may recommend you get plenty of rest and avoid heavy exercise for at least 3–6 months to allow the heart to heal. They may then recommend physical rehabilitation to strengthen your heart.
  • Heart pump:In the case of low blood pressure, a temporary heart pump may be used to regulate it.
  • Pericardial tap:In emergency situations, a pericardial tap may help drain excess fluids that are putting pressure on the heart.
  • Heart transplant:If your condition is very severe and doesn’t respond to other treatments, you may need a heart transplant.

Myocarditis and pericarditis are similar inflammatory cardiac conditions that often manifest at the same time. Myocarditis affects the heart muscle, while pericarditis affects the membrane that lines the heart.

Both conditions can often fully resolve with noninvasive interventions like certain medications and getting plenty of rest. If you’re experiencing symptoms like chest pain, pressure, or tightness, visit a doctor for a diagnosis.

Doctors can diagnose both conditions with an electrocardiography (ECG), and they are typically highly treatable.