Myocarditis: Causes, Symptoms, and Treatment
Medically reviewed by Achuta Uppu, MD, Internal Medicine. Last reviewed: October 23, 2026.
What kind of doctor treats Myocarditis?
A cardiologist, a doctor who treats heart disease, usually leads care for myocarditis. It is inflammation of the heart muscle. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What is myocarditis?
Myocarditis is inflammation of the heart muscle. It is an uncommon disorder.
When an infection affects the heart, disease-fighting cells enter the heart. The chemicals made by these cells can also damage the heart muscle. As a result, the heart can become thick, swollen, and weak.
Most cases are mild and improve with standard medical therapy. In a minority of cases the symptoms do not improve or become recurrent. Some people recover completely. Others may have lasting heart failure.
Symptoms
There may be no symptoms. Symptoms may be similar to the flu. In most cases, symptoms come a few days to weeks after a flu-like illness.
If symptoms occur, they may include:
- Chest pain that may resemble a heart attack.
- Fatigue.
- Fever and other signs of infection, including headache, muscle aches, sore throat, diarrhea, or rashes.
- Leg swelling.
- Rapid breathing, a rapid heart rate, or shortness of breath.
- Fainting, often related to irregular heart rhythms, or low urine output.
Causes and who gets it
Most of the time, myocarditis is caused by an infection that reaches the heart. Many cases are caused by a virus that reaches the heart. These include the viruses that cause COVID-19 and the flu, coxsackievirus, parvovirus, cytomegalovirus, and adenovirus. Bacterial infections such as Lyme disease and strep can also cause it.
Other causes include:
- Reactions to some medicines, such as some chemotherapy drugs.
- Exposure to chemicals in the environment, such as heavy metals.
- Infections due to fungus or parasites.
- Radiation.
- Autoimmune disease, which causes inflammation throughout the body.
Myocarditis after COVID-19 vaccination has been reported, but it is very rare. Sometimes the cause is never found.
Myocarditis is not inherited. It is most often found in young adults, and men are affected more often than women.
How doctors diagnose it
Myocarditis can be hard to diagnose. Its signs often look like other heart and lung diseases, or a bad case of the flu.
The provider may hear a rapid heartbeat or abnormal heart sounds with a stethoscope. Tests may include:
- A chest x-ray, which can show an enlarged heart.
- An electrocardiogram (ECG), an echocardiogram (heart ultrasound), and a cardiac MRI.
- A heart biopsy, which is the most accurate way to confirm it but is not always needed.
No blood test can confirm myocarditis by itself. A high troponin level with no other explanation supports the diagnosis. Troponin is a blood test that shows heart muscle damage.
Treatment
Treatment is aimed at the cause of the problem. It may involve:
- Antibiotics to fight bacterial infection.
- Steroids, medicines that reduce swelling and inflammation. Other drugs that block the immune system are generally not used for the most common forms of myocarditis in adults. They may be considered for specific forms such as giant cell myocarditis.
- Diuretics to remove extra water from the body.
- A low-salt diet and less activity.
If the heart muscle is weak, your provider will prescribe medicines to treat heart failure. You may also need a pacemaker or a similar device to correct a dangerous abnormal heartbeat.
Some people with severe myocarditis need a temporary heart pump to survive the acute injury. Rarely, a heart transplant may be needed if the heart muscle is too weak.
Sports during acute viral myocarditis may cause sudden death. Avoid high levels of physical activity for at least 3 to 6 months after the diagnosis. Avoid pain medicines called NSAIDs, such as ibuprofen. They may increase inflammation.
People with severe myocarditis should see heart doctors who know about heart failure and heart rhythm problems.
When to see a doctor
Contact your provider if you have symptoms of myocarditis, especially after a recent infection.
If you have chest pain or severe shortness of breath, or your symptoms get worse, call 9-1-1 or get medical help right away. Call 911 or go to the emergency room if you faint or suddenly feel confused.
If you have myocarditis and have more swelling, get medical help right away.
How a direct primary care or concierge doctor fits in
A direct primary care doctor charges a flat monthly fee instead of billing insurance, while a concierge doctor usually charges more and often works alongside insurance. A direct primary care doctor can review your medicines, arrange follow-up visits, and work with a cardiologist.
Common questions
Is myocarditis serious?
It can be serious, because it may cause lasting heart failure. Still, most cases are mild and improve with standard medical therapy.
Can I exercise or play sports with myocarditis?
Not at a high level for at least 3 to 6 months after the diagnosis. Sports during acute viral myocarditis may cause sudden death.
Can the COVID-19 vaccine cause myocarditis?
Rarely. Myocarditis after COVID-19 vaccination has been reported, but it is very rare.
Is ibuprofen safe to take with myocarditis?
No. Avoid pain medicines called NSAIDs, such as ibuprofen. They may increase inflammation. Ask your doctor which pain medicine is safe for you.
Sources
- MedlinePlus - Myocarditis (Medical Encyclopedia)
- NORD - Myocarditis
- NHLBI - Heart Inflammation Symptoms
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
