The cause of constrictive pericarditis in the developing world are idiopathic in origin, though likely infectious in nature. In regions where tuberculosis is common, it is the cause in a large portion of cases.

Causes of constrictive pericarditis include:

- Tuberculosis

- Incomplete drainage of purulent pericarditis

- Fungal and parasitic infections

- Chronic pericarditis

- Postviral pericarditis

- Postsurgical

- Following MI, post-myocardial infarction

- In association with pulmonary asbestos

The frequency of tamponade is unclear. One estimate from the United States places it at 2 per 10,000 per year. It is estimated to occur in 2% of those with stab or gunshot wounds to the chest.

There are several causes of acute pericarditis. In developed nations, the cause of most (80–90%) cases of acute pericarditis is unknown but a viral cause is suspected in the majority of such cases. The other 10–20% of acute pericarditis cases have various causes including connective tissue diseases (e.g., systemic lupus erythematosus), cancer, or involve an inflammatory reaction of the pericardium following trauma to the heart such as after a heart attack such as Dressler's syndrome. Familial mediterranean fever and TNF receptor associated periodic syndrome are rare inherited autoimmune diseases capable of causing recurring episodes of acute pericarditis.

About 30% of people with viral pericarditis or pericarditis of an unknown cause have one or several recurrent episodes.

The definitive treatment for constrictive pericarditis is pericardial stripping, which is a surgical procedure where the entire pericardium is peeled away from the heart. This procedure has significant risk involved, with mortality rates of 6% or higher in major referral centers.

A poor outcome is almost always the result after a pericardiectomy is performed for constrictive pericarditis whose origin was radiation-induced, further some patients may develop heart failure post-operatively.

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

Pericarditis may be caused by viral, bacterial, or fungal infection.

In the developed world viruses are believed to be the cause of about 85% of cases. In the developing world tuberculosis is a common cause but it is rare in the developed world.

Viral causes include coxsackievirus, herpesvirus, mumps virus, and HIV among others.

Pneumococcus or tuberculous pericarditis are the most common bacterial forms. Anaerobic bacteria can also be a rare cause. Fungal pericarditis is usually due to histoplasmosis, or in immunocompromised hosts Aspergillus, Candida, and Coccidioides. The most common cause of pericarditis worldwide is infectious pericarditis with tuberculosis.

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.

Cardiac tamponade is caused by a large or uncontrolled pericardial effusion, i.e. the buildup of fluid inside the pericardium. This commonly occurs as a result of chest trauma (both blunt and penetrating), but can also be caused by myocardial rupture, cancer, uremia, pericarditis, or cardiac surgery, and rarely occurs during retrograde aortic dissection, or while the person is taking anticoagulant therapy. The effusion can occur rapidly (as in the case of trauma or myocardial rupture), or over a more gradual period of time (as in cancer). The fluid involved is often blood, but pus is also found in some circumstances.

Causes of increased pericardial effusion include hypothyroidism, physical trauma (either penetrating trauma involving the pericardium or blunt chest trauma), pericarditis (inflammation of the pericardium), iatrogenic trauma (during an invasive procedure), and myocardial rupture.

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.

It is believed to result from an autoimmune inflammatory reaction to myocardial neo-antigens formed as a result of the MI. A similar pericarditis can be associated with any pericardiotomy or trauma to the pericardium or heart surgery.

It may be:

- "transudative" (congestive heart failure, myxoedema, nephrotic syndrome),

- "exudative" (tuberculosis, spread from empyema)

- "hemorrhagic" (trauma, rupture of aneurysms, malignant effusion).

- "malignant" (due to fluid accumulation caused by metastasis)

The most common causes of pericardial effusion have changed over time and vary depending on geography and the population in question. When pericardial effusion is suspected, echocardiography usually confirms the diagnosis and allows assessment for signs of hemodynamic instability. Cross-sectional imaging with computed tomography (CT) can help to localize and quantify (as in a loculated effusion) or assess for pericardial pathology (pericardial thickening, constrictive pericarditis).

The pleural space can be invaded by fluid, air, and particles from different parts of the body which fairly complicates the diagnosis. Viral infection (coxsackie B virus, HRSV, CMV, adenovirus, EBV, parainfluenza, influenza) is the most common cause of pleurisy. However, many other different conditions can cause pleuritic chest pain:

- Aortic dissections

- Autoimmune disorders such as systemic lupus erythematosus (or drug-induced lupus erythematosus), Autoimmune hepatitis (AIH), rheumatoid arthritis and Behçet's disease.

- Bacterial infections associated with pneumonia and tuberculosis

- Chest injuries (blunt or penetrating)

- Familial Mediterranean fever, an inherited condition that often causes fever and swelling in the abdomen or the lungs

- Fungal or parasitic infections

- Heart surgery, especially coronary-artery bypass grafting

- Cardiac problems (ischemia, pericarditis)

- Inflammatory bowel disease

- Lung cancer and lymphoma

- Other lung diseases like cystic fibrosis, sarcoidosis, asbestosis, lymphangioleiomyomatosis, and mesothelioma

- Pneumothorax

- Pulmonary embolisms, which are blood clots that enter the lungs

When the space between the pleurae starts to fill with fluid, as in pleural effusion, the chest pain can be eased but a shortness of breath can result, since the lungs need room to expand during breathing. Some cases of pleuritic chest pain are idiopathic, which means that the exact cause cannot be determined.

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.

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.

Uremic pericarditis is a form of pericarditis. It causes fibrinous pericarditis. The main cause of the disease is poorly understood.

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.

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.

A complication that may occur in the acute setting soon after a myocardial infarction or in the weeks following is cardiogenic shock. Cardiogenic shock is defined as a hemodynamic state in which the heart cannot produce enough of a cardiac output to supply an adequate amount of oxygenated blood to the tissues of the body.

While the data on performing interventions on individuals with cardiogenic shock is sparse, trial data suggests a long-term mortality benefit in undergoing revascularization if the individual is less than 75 years old and if the onset of the acute myocardial infarction is less than 36 hours and the onset of cardiogenic shock is less than 18 hours. If the patient with cardiogenic shock is not going to be revascularized, aggressive hemodynamic support is warranted, with insertion of an intra-aortic balloon pump if not contraindicated. If diagnostic coronary angiography does not reveal a culprit blockage that is the cause of the cardiogenic shock, the prognosis is poor.

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

The exact incidence of myocarditis is unknown. However, in series of routine autopsies, 1–9% of all patients had evidence of myocardial inflammation. In young adults, up to 20% of all cases of sudden death are due to myocarditis.

Among patients with HIV, myocarditis is the most common cardiac pathological finding at autopsy, with a prevalence of 50% or more.

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.

Endomyocardial fibrosis is generally limited to the tropics and sub-saharan Africa. The highest incidence of death caused by cardiac sarcoidosis is found in Japan.

A large number of causes of myocarditis have been identified, but often a cause cannot be found. In Europe and North America, viruses are common culprits. Worldwide, however, the most common cause is Chagas' disease, an illness endemic to Central and South America that is due to infection by the protozoan "Trypanosoma cruzi". Many of the causes listed below, particularly those involving protozoa, fungi, parasites, allergy, autoimmune disorders, and drugs are also causes of eosinophilic myocarditis.

Costochondritis is a common condition and is responsible for 30% of emergency room chest pain related visits. One-fifth of visits to the primary care physician are for musculoskeletal chest pain; of this 20% of primary care office visits, 13% is due to costochondritis. Costochondritis cases are most often seen in people older than age 40 and occurs more often in women.