The classic sign of pericarditis is a friction rub heard with a stethoscope on the cardiovascular examination usually on the lower left sternal border. Other physical signs include a patient in distress, positional chest pain, diaphoresis (excessive sweating), and possibility of heart failure in form of pericardial tamponade causing pulsus paradoxus, and the Beck's triad of low blood pressure (due to decreased cardiac output), distant (muffled) heart sounds, and distension of the jugular vein (JVD).

Pericarditis can progress to pericardial effusion and eventually cardiac tamponade. This can be seen in patients who are experiencing the classic signs of pericarditis but then show signs of relief, and progress to show signs of cardiac tamponade which include decreased alertness and lethargy, pulsus paradoxus (decrease of at least 10 mmHg of the systolic blood pressure upon inspiration), low blood pressure (due to decreased cardiac index), (jugular vein distention from right sided heart failure and fluid overload), distant heart sounds on auscultation, and equilibration of all the diastolic blood pressures on cardiac catheterization due to the constriction of the pericardium by the fluid.

In such cases of cardiac tamponade, EKG or Holter monitor will then depict electrical alternans indicating wobbling of the heart in the fluid filled pericardium, and the capillary refill might decrease, as well as severe vascular collapse and altered mental status due to hypoperfusion of body organs by a heart that can not pump out blood effectively.

The diagnosis of tamponade can be confirmed with trans-thoracic echocardiography (TTE), which should show a large pericardial effusion and diastolic collapse of the right ventricle and right atrium. Chest X-ray usually shows an enlarged cardiac silhouette ("water bottle" appearance) and clear lungs. Pulmonary congestion is typically not seen because equalization of diastolic pressures constrains the pulmonary capillary wedge pressure to the intra-pericardial pressure (and all other diastolic pressures).

Chest pain is one of the common symptoms of acute pericarditis. It is usually of sudden onset, occurring in the anterior chest and often has a sharp quality that worsens with breathing in or coughing, due to inflammation of the pleural surface at the same time. The pain may be reduced with sitting up and leaning forward while worsened with lying down, and also may radiate to the back, to one or both trapezius ridges. However, the pain can also be dull and steady, resembling the chest pain in an acute myocardial infarction. As with any chest pain, other causes must also be ruled out, such as GERD, pulmonary embolism, muscular pain, etc.

A pericardial friction rub is a very specific sign of acute pericarditis, meaning the presence of this sign invariably indicates presence of disease. However, absence of this sign does not rule out disease. This rub can be best heard by the diaphragm of the stethoscope at the left sternal border arising as a squeaky or scratching sound, resembling the sound of leather rubbing against each other. This sound should be distinguished from the sound of a murmur, which is similar but sounds more like a "swish" sound than a scratching sound. The pericardial rub is said to be generated from the friction generated by the two inflamed layers of the pericardium; however, even a large pericardial effusion does not necessarily present a rub. The rub is best heard during the maximal movement of the heart within the pericardial sac, namely, during atrial systole, ventricular systole, and the filling phase of early ventricular diastole.

Fever may be present since this is an inflammatory process.

Clinical presentation of diseases of pericardium may vary between:

- Acute and recurrent pericarditis

- Pericardial effusion without major hemodynamic compromise

- Cardiac tamponade

- Constrictive pericarditis

- Effusive-constrictive pericarditis

Signs and symptoms of constrictive pericarditis are consistent with the following: fatigue, swollen abdomen, difficulty breathing (dyspnea), swelling of legs and general weakness. Related conditions are bacterial pericarditis, pericarditis and pericarditis after a heart attack.

The signs and symptoms associated with myocarditis are varied, and relate either to the actual inflammation of the myocardium or to the weakness of the heart muscle that is secondary to the inflammation. Signs and symptoms of myocarditis include the following:

- Chest pain (often described as "stabbing" in character)

- Congestive heart failure (leading to swelling, shortness of breath and liver congestion)

- Palpitations (due to abnormal heart rhythms)

- Sudden death (in young adults, myocarditis causes up to 20% of all cases of sudden death)

- Fever (especially when infectious, e.g. in rheumatic fever)

- Symptoms in young children tend to be more nonspecific, with generalized malaise, poor appetite, abdominal pain, and chronic cough. Later stages of the illness will present with respiratory symptoms with increased work of breathing, and is often mistaken for asthma.

Since myocarditis is often due to a viral illness, many patients give a history of symptoms consistent with a recent viral infection, including fever, rash, diarrhea, joint pains, and easily becoming tired.

Myocarditis is often associated with pericarditis, and many people with myocarditis present with signs and symptoms that suggest myocarditis and pericarditis at the same time.

Uremic pericarditis is correlated to the degree of azotemia in the system. BUN is normally >60 mg/dL (normal is 7–20 mg/dL). The pathogenesis is poorly understood.

Fibrinous pericarditis is an exudative inflammation. The pericardium is infiltrated by the fibrinous exudate. This consists of fibrin strands and leukocytes. Fibrin describes an amorphous, eosinophilic (pink) network. Leukocytes (white blood cells; mainly neutrophils) are found within the fibrin deposits and intrapericardic. Vascular congestion is also present. Inflammatory cells do not penetrate the myocardium (as is seen with other presentations of pericarditis), and as a result, this particular variant does not present with diffuse ST elevation on ECG (a classic sign of pericarditis known as stage I ECG changes which are seen with other causes). To naked eye examination, this pathology is referred to as having a "Bread and Butter Appearance".

Myopericarditis is a combination of both myocarditis and pericarditis appearing in a single individual, namely inflammation of both the pericardium and the heart muscle. It can involve the presence of fluid in the heart. Myopericarditis refers primarily to a pericarditis with lesser myocarditis, as opposed to a perimyocarditis, though the two terms are often used interchangeably. Both will be reflected on an ECG. Myo-pericarditis usually involves inflammation of the pericardium, or the sac covering the heart.

The ACAM2000 smallpox vaccine has been known to cause myopericarditis in some people.

Carditis is the inflammation of the heart or its surroundings. The plural of carditis is carditides.

It is usually studied and treated by specifying it as:

- Pericarditis is the inflammation of the pericardium

- Myocarditis is the inflammation of the heart muscle

- Endocarditis is the inflammation of the endocardium

- Pancarditis is the inflammation of the entire heart: the epicardium, the myocardium and the endocardium

- Reflux carditis refers to a possible outcome of esophageal reflux (also known as GERD), and involves inflammation of the esophagus/stomach mucosa

Dressler syndrome was, historically, a phenomenon complicating about 7% of myocardial infarctions; however, in the era of percutaneous coronary intervention, it is very uncommon. The disease consists of a persistent low-grade fever, chest pain (usually pleuritic in nature), pericarditis (usually evidenced by a pericardial friction rub), and/or a pericardial effusion. The symptoms tend to occur 2–3 weeks after myocardial infarction, but can also be delayed for a few months. It tends to subside in a few days, and very rarely leads to pericardial tamponade. An elevated ESR is an objective, yet nonspecific, laboratory finding.

Constrictive pericarditis is a medical condition characterized by a thickened, fibrotic pericardium, limiting the heart's ability to function normally. In many cases, the condition continues to be difficult to diagnose and therefore benefits from a good understanding of the underlying cause.

Myocarditis, also known as inflammatory cardiomyopathy, is inflammation of the heart muscle. Symptoms can include shortness of breath, chest pain, decreased ability to exercise, and an irregular heartbeat. The duration of problems can vary from hours to months. Complications may include heart failure due to dilated cardiomyopathy or cardiac arrest.

Myocarditis is most often due to a viral infection. Other causes include bacterial infections, certain medications, toxins, and autoimmune disorders. A diagnosis may be supported by an electrocardiogram (ECG), increased troponin, heart MRI, and occasionally a heart biopsy. An ultrasound of the heart is important to rule out other potential causes such as heart valve problems.

Treatment depends on both the severity and the cause. Medications such as ACE inhibitors, beta blockers, and diuretics are often used. A period of no exercise is typically recommended during recovery. Corticosteroids or intravenous immunoglobulin (IVIG) may be useful in certain cases. In severe cases an implantable cardiac defibrillator or heart transplant may be recommended.

In 2013, about 1.5 million cases of acute myocarditis occurred. While people of all ages are affected, the young are most often affected. It is slightly more common in males than females. Most cases are mild. In 2015 cardiomyopathy, including myocarditis, resulted in 354,000 deaths up from 294,000 in 1990. The initial descriptions of the condition are from the mid-1800s.

Dressler syndrome needs to be differentiated from pulmonary embolism, another identifiable cause of pleuritic (and non-pleuritic) chest pain in people who have been hospitalized and/or undergone surgical procedures within the preceding weeks.

Chest pain or pressure are common symptoms. A small effusion may be asymptomatic. Larger effusions may cause cardiac tamponade, a life-threatening complication; signs of impending tamponade include dyspnea, low blood pressure, and distant heart sounds.

The so-called "water-bottle heart" is a radiographic sign of pericardial effusion, in which the cardiopericardial silhouette is enlarged and assumes the shape of a flask or water bottle.

It can be associated with dullness to percussion over the left subscapular area due to compression of the left lung base. This phenomenon is known as Ewart's sign.

The defining symptom of pleurisy is a sudden sharp, stabbing, burning or dull pain in the right or left side of the chest during breathing, especially when one inhales and exhales. It feels worse with deep breathing, coughing, sneezing, or laughing. The pain may stay in one place, or it may spread to the shoulder or back. Sometimes, it becomes a fairly constant dull ache.

Depending on its cause, pleuritic chest pain may be accompanied by other symptoms:

- Dry cough

- Fever and chills

- Rapid, shallow breathing

- Shortness of breath

- Fast heart rate

- Sore throat followed by pain and swelling in the joints

Onset may be rapid or more gradual. Symptoms typically include those of cardiogenic shock including shortness of breath, weakness, lightheadedness, and cough. Other symptoms may relate to the underlying cause.

Pericardial effusion ("fluid around the heart") is an abnormal accumulation of fluid in the pericardial cavity. Because of the limited amount of space in the pericardial cavity, fluid accumulation leads to an increased intrapericardial pressure which can negatively affect heart function. A pericardial effusion with enough pressure to adversely affect heart function is called cardiac tamponade. Pericardial effusion usually results from a disturbed equilibrium between the production and re-absorption of pericardial fluid, or from a structural abnormality that allows fluid to enter the pericardial cavity.

Normal levels of pericardial fluid are from 15 to 50 mL.

Pleurisy, also known as pleuritis, is inflammation of the membranes (pleurae) that surround the lungs and line the chest cavity. This can result in a sharp chest pain with breathing. Occasionally the pain may be a constant dull ache. Other symptoms may include shortness of breath, cough, fever, or weight loss depending on the underlying cause.

The most common cause is a viral infection. Other causes include pneumonia, pulmonary embolism, autoimmune disorders, lung cancer, following heart surgery, pancreatitis, chest trauma, and asbestosis. Occasionally the cause remains unknown. The underlying mechanism involves the rubbing together of the pleurae instead of smooth gliding. Other conditions that can produce similar symptoms include pericarditis, heart attack, cholecystitis, and pneumothorax. Diagnosis may include a chest X-ray, electrocardiogram (ECG), and blood tests.

Treatment depends on the underlying cause. Paracetamol and ibuprofen may be used to help with the pain. Incentive spirometry may be recommended to encourage larger breaths. About one million people are affected in the United States each year. Descriptions of the condition date from at least as early as 400 BC by Hippocrates.

Myocardial infarction complications may occur immediately following a heart attack (in the acute phase), or may need time to develop (a chronic problem). After an infarction, an obvious complication is a second infarction, which may occur in the domain of another atherosclerotic coronary artery, or in the same zone if there are any live cells left in the infarct.

A myocardial infarction may compromise the function of the heart as a pump for the circulation, a state called heart failure. There are different types of heart failure; left- or right-sided (or bilateral) heart failure may occur depending on the affected part of the heart, and it is a low-output type of failure. If one of the heart valves is affected, this may cause dysfunction, such as mitral regurgitation in the case of left-sided coronary occlusion that disrupts the blood supply of the papillary muscles. The incidence of heart failure is particularly high in patients with diabetes and requires special management strategies.

Cardiac tamponade, also known as pericardial tamponade, is when fluid in the pericardium (the sac around the heart) builds up and results in compression of the heart. Onset may be rapid or more gradual. Symptoms typically include those of cardiogenic shock including shortness of breath, weakness, lightheadedness, and cough. Other symptoms may relate to the underlying cause.

Common causes include cancer, kidney failure, chest trauma, and pericarditis. Other causes include connective tissue diseases, hypothyroidism, aortic rupture, and following cardiac surgery. In Africa, tuberculosis is a relatively common cause.

Diagnosis may be suspected based on low blood pressure, jugular venous distension, pericardial rub, or quiet heart sounds. The diagnosis may be further supported by specific electrocardiogram (ECG) changes, chest X-ray, or an ultrasound of the heart. If fluid increases slowly the pericardial sac can expand to contain more than 2 liters; however, if the increase is rapid as little as 200 mL can result in tamponade.

When tamponade results in symptoms, drainage is necessary. This can be done by pericardiocentesis, surgery to create a pericardial window, or a pericardiectomy. Drainage may also be necessary to rule out infection or cancer. Other treatments may include the use of dobutamine or in those with low blood volume, intravenous fluids. Those with few symptoms and no worrisome features can often be closely followed. The frequency of tamponade is unclear. One estimate from the United States places it at 2 per 10,000 per year.

Chest pain is the most common symptom of acute myocardial infarction and is often described as a sensation of tightness, pressure, or squeezing. Pain radiates most often to the left arm, but may also radiate to the lower jaw, neck, right arm, back, and upper abdomen. The pain most suggestive of an acute MI, with the highest likelihood ratio, is pain radiating to the right arm and shoulder. Similarly, chest pain similar to a previous heart attack is also suggestive. The pain associated with MI is usually diffuse, does not change with position, and lasts for more than 20 minutes. Levine's sign, in which a person localizes the chest pain by clenching one or both fists over their sternum, has classically been thought to be predictive of cardiac chest pain, although a prospective observational study showed it had a poor positive predictive value. Pain that responds to nitroglycerin does not indicate the presence or absence of a myocardial infarction.

Myocardial infarction (MI) refers to tissue death (infarction) of the heart muscle (myocardium). It is a type of acute coronary syndrome, which describes a sudden or short-term change in symptoms related to blood flow to the heart. Unlike other causes of acute coronary syndromes, such as unstable angina, a myocardial infarction occurs when there is cell death, as measured by a blood test for biomarkers (the cardiac protein troponin or the cardiac enzyme CK-MB). When there is evidence of an MI, it may be classified as an ST elevation myocardial infarction (STEMI) or Non-ST elevation myocardial infarction (NSTEMI) based on the results of an ECG.

The phrase "heart attack" is often used non-specifically to refer to a myocardial infarction and to sudden cardiac death. An MI is different from—but can cause—cardiac arrest, where the heart is not contracting at all or so poorly that all vital organs cease to function, thus causing death. It is also distinct from heart failure, in which the pumping action of the heart is impaired. However, an MI may lead to heart failure.

Tuberculous pericarditis is a form of pericarditis.

Pericarditis caused by tuberculosis is difficult to diagnose, because definitive diagnosis requires culturing "Mycobacterium tuberculosis" from aspirated pericardial fluid or pericardial , which requires high technical skill and is often not diagnostic (the yield from culture is low even with optimum specimens). The Tygerberg scoring system helps the clinician to decide whether pericarditis is due to tuberculosis or whether it is due to another cause: night sweats (1 point), weight loss (1 point), fever (2 point), serum globulin > 40g/l (3 points), blood total leucocyte count <10 x 10/l (3 points); a total score of 6 or more is highly suggestive of tuberculous pericarditis. Pericardial fluid with an interferon-γ level greater than 50/ml is highly specific for tuberculous pericarditis.

There are no randomized trials which evaluate the length of anti-tuberculosis treatment required for tuberculous pericarditis. There is a small but not conclusive benefit for treatment with a schedule of steroids with anti-tuberculosis drugs. Open surgical drainage of fluid though effective in preventing cardiac tamponade was associated with more deaths.