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Health condition

Myocarditis and pericarditis, the muscle, the sac, and how each is treated.

Two related but distinct kinds of heart inflammation, often triggered by the same virus and frequently seen together. Here is how they are told apart and managed.

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A heart imaging scan softly lit on a screen

Why trust this guide

  • 01

    Editorial team

    Written by our editorial team from the UK sources listed on each page.

  • 02

    Sourced from guidance

    Checked against ESC, NICE and peer-reviewed cardiology sources you can see at the end.

  • 03

    Current for 2026

    Reflects modern ESC pericarditis guidance, activity-restriction advice and MDT cardiology pathways.

Key facts

Both conditions, at a glance.

The essentials, in plain English - what each condition is, how they overlap, and how they're managed in the UK today.

  • Myocarditis

    Inflammation of the heart muscle itself - usually viral or autoimmune, can affect the pumping function and cause arrhythmia.

  • Pericarditis

    Inflammation of the pericardial sac around the heart - usually viral or idiopathic, causes sharp chest pain relieved by sitting forward.

  • Myopericarditis

    The two conditions frequently overlap - inflammation of the sac with some muscle involvement, sharing symptoms and causes.

  • Assessment

    ECG, troponin, CRP, echocardiogram and cardiac MRI, following an ESC-guided pathway - with cardiology input from the outset.

  • First-line therapy

    NSAIDs and colchicine for pericarditis; activity restriction for both conditions while the heart settles.

  • Emergency features

    Cardiac tamponade, cardiogenic shock or ventricular arrhythmia need immediate hospital care, not a routine appointment.

Looking for detail on just one condition? Read our dedicated guides to myocarditis or pericarditis on their own.

Why this guide matters

Two conditions, one careful pathway.

Myocarditis and pericarditis are frequently confused, often co-occur, and carry very different risk profiles. The three points below shape everything else on this page.

  • They are not the same condition

    Pericarditis affects the sac around the heart and is usually straightforward; myocarditis affects the muscle itself and carries a higher risk of arrhythmia.

  • The overlap is common, not rare

    Myopericarditis - inflammation of both structures together - is a recognised pattern, particularly after a viral illness.

  • Activity restriction protects recovery

    Avoiding strenuous exercise for three to six months, agreed with cardiology, is central to safe recovery from either condition.

How the diagnosis is made

From chest pain to a clear diagnosis.

The ESC-guided steps a UK cardiology team will normally follow, in order - so you know what to expect and why.

  1. 01

    Assessing

    History and examination

    Character of the chest pain, recent viral illness, and listening for a pericardial friction rub - a scratchy sound heard with each heartbeat.

  2. 02

    Assessing

    12-lead ECG

    Widespread, saddle-shaped ST elevation points to pericarditis; diffuse changes or arrhythmia raise concern for myocardial involvement.

  3. 03

    Assessing

    Troponin and inflammatory markers

    A raised troponin signals myocardial injury (myocarditis); CRP and ESR track the overall inflammatory burden in both conditions.

  4. 04

    Confirming

    Echocardiogram

    Looks for a pericardial effusion, its size and any sign of tamponade, plus overall pumping function if myocarditis is suspected.

  5. 05

    Confirming

    Cardiac MRI

    The key test for myocarditis - late gadolinium enhancement and oedema confirm muscle inflammation and map its extent.

  6. 06

    Preparing

    Specialist cardiology referral

    Confirmed or suspected myocarditis, recurrent pericarditis, or an effusion of any size warrants an MDT-led cardiology opinion.

  7. 07

    Preparing

    Activity-restriction plan

    A structured return-to-activity plan, typically over three to six months, agreed with cardiology before resuming strenuous exercise.

Typical timeline: same-day assessment, results and referral within days.

Symptoms

How to tell them apart.

Overlapping features with a few tells - and the signs that mean it's time to call 999 rather than book an appointment.

  • Sharp, pleuritic chest pain

    Classic of pericarditis - sharp, worse lying flat or on deep breathing, and eased by sitting forward.

  • Dull, pressure-like chest pain

    More typical of myocarditis - a heavier, central discomfort that can mimic a heart attack.

  • Pericardial friction rub

    A scratchy, to-and-fro sound heard on auscultation - a hallmark clinical sign of pericarditis.

  • Breathlessness

    Can reflect a large pericardial effusion, reduced pumping function, or both together.

  • Palpitations and arrhythmia

    Irregular or racing heartbeats - a feature of myocarditis that needs prompt cardiology assessment.

  • Fever and viral prodrome

    A recent cold, flu or gastrointestinal illness often precedes both conditions by one to two weeks.

  • Fatigue and exercise intolerance

    Reduced stamina and unusual tiredness on exertion, especially where the heart muscle is involved.

  • Red flag - collapse or shock

    Fainting, cold clammy skin or a drop in blood pressure signal tamponade or cardiogenic shock - call 999.

Treatment

How both conditions are managed.

NSAIDs and colchicine first for pericarditis, activity restriction for both, and emergency drainage or MDT cardiology care where needed.

  • NSAIDs

    First-line for pericarditis - ibuprofen or aspirin at anti-inflammatory doses, tapered over weeks under guidance.

  • Colchicine

    Added alongside NSAIDs to reduce recurrence risk in pericarditis - now standard first-line combination therapy.

  • Activity restriction

    Avoiding strenuous exercise for three to six months in both conditions, given the risk of arrhythmia and further injury.

  • Heart failure management

    ACE inhibitors, beta-blockers and diuretics where myocarditis has significantly reduced pumping function.

  • Corticosteroids

    Reserved for refractory or autoimmune-driven cases that fail to settle with NSAIDs and colchicine alone.

  • Rhythm monitoring

    Continuous ECG monitoring where myocarditis carries a meaningful arrhythmia risk, sometimes with an implantable monitor.

  • Pericardiocentesis

    Emergency drainage of a large effusion or tamponade - a needle or catheter procedure performed under imaging guidance.

  • MDT specialist cardiology care

    Complex, recurrent or myocarditis-associated cases are best managed jointly across cardiology, imaging and rheumatology where relevant.

What this guide is based on

The sources behind every claim on this page.

European and UK national cardiology guidance, current at the time of last review.

Key references

Guidelines and standards we relied on.

A quiet reminder

This guide is for information, not medical advice.

Your GP or cardiologist knows your history and can tell you which parts apply to you. If in doubt, get seen.

  • European Society of Cardiology (ESC). Guidelines for the diagnosis and management of pericardial diseases.

  • ESC. Position statement on myocarditis - diagnosis, treatment and follow-up.

  • NICE Clinical Knowledge Summaries. Pericarditis and myocarditis.

  • British Heart Foundation. Patient information on myocarditis and pericarditis.

Red flags

When either condition needs urgent attention.

Most cases are manageable with cardiology follow-up. These are the situations that aren't - and where emergency care is needed.

  • Cardiac tamponade

    Rapid fluid build-up around the heart compressing it - breathlessness, low blood pressure and distended neck veins need a 999 call.

  • Cardiogenic shock

    Severe myocardial involvement causing the heart to fail as a pump - cold, clammy skin, confusion and collapse are emergencies.

  • Ventricular arrhythmia

    Fast, irregular heart rhythms from inflamed muscle can be life-threatening and need immediate hospital assessment.

  • Chest pain with breathlessness

    New or worsening chest pain with shortness of breath should never be assumed to be pericarditis without assessment.

  • Fainting or near-fainting

    Syncope alongside chest symptoms suggests a significant rhythm or pumping problem - seek urgent review.

  • Recurrent pericarditis

    Repeated flares after stopping treatment need specialist input on colchicine duration and, occasionally, immunosuppression.

  • Fulminant myocarditis

    A rapid, severe presentation with heart failure within days of viral illness - a critical-care emergency.

  • Chest pain during exercise restriction

    New symptoms during the recovery period should prompt an early review before resuming any activity.

  • Post-vaccination or post-infective chest pain

    New chest pain in the days after a vaccination or infection warrants prompt cardiology assessment rather than reassurance alone.

Living with it

Recovery takes months, not weeks.

Four things that make the biggest difference during recovery - respecting the activity restriction, finishing your medication, keeping follow-up appointments and acting fast on new symptoms.

A quiet reminder

Most people recover fully.

With the right activity restriction and follow-up, the majority of people with myocarditis or pericarditis return to normal life and normal exercise.

  1. 01 Rest

    Respect the activity restriction

    Three to six months without strenuous exercise feels excessive but genuinely protects a healing heart - build back up gradually with cardiology guidance.

  2. 02 Adherence

    Finish the anti-inflammatory course

    Stopping NSAIDs or colchicine early is the single biggest driver of pericarditis relapse - taper only as advised.

  3. 03 Monitor

    Know your follow-up plan

    Repeat echocardiograms or cardiac MRI track recovery - keep every follow-up appointment even once you feel well.

  4. 04 Escalate

    Act fast on new symptoms

    New breathlessness, palpitations or chest pain during recovery deserves same-day review, not a wait-and-see approach.

Frequently asked

Everything we get asked about myocarditis and pericarditis.

Quick answers on causes, diagnosis, treatment and when to worry.

  • What is the difference between myocarditis and pericarditis?

    Myocarditis is inflammation of the heart muscle itself, which can affect pumping function and rhythm. Pericarditis is inflammation of the pericardial sac surrounding the heart, causing sharp chest pain. The two often overlap as myopericarditis, sharing viral causes and overlapping symptoms.

  • What causes myocarditis and pericarditis?

    Viral infection is the most common trigger for both. Autoimmune conditions, certain medications, and rarely vaccination or other inflammatory triggers can also cause them. In many cases no specific cause is ever identified, which is normal and does not change the treatment approach.

  • How is pericarditis diagnosed?

    A combination of the characteristic pleuritic chest pain, a pericardial friction rub on examination, widespread saddle-shaped ST elevation on ECG, raised inflammatory markers and evidence of an effusion on echocardiogram. Cardiac MRI can add detail in atypical or recurrent cases.

  • Why is exercise restricted for so long?

    Strenuous exercise during active inflammation raises the risk of arrhythmia and can worsen myocardial injury. A three to six month restriction, agreed with cardiology and often confirmed by repeat imaging, allows the heart to heal fully before returning to full activity.

  • What is the first-line treatment for pericarditis?

    NSAIDs combined with colchicine, tapered gradually over several weeks under specialist guidance. This combination reduces both symptoms and the risk of recurrence more effectively than NSAIDs alone.

  • When is myocarditis or pericarditis an emergency?

    Cardiac tamponade, cardiogenic shock, ventricular arrhythmia, fainting or fulminant myocarditis all need immediate emergency care. Any new chest pain with breathlessness, collapse or a fast irregular heartbeat should prompt a 999 call rather than waiting for a routine appointment.

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