Pericarditis occurs when the pericardium (a membrane around the heart) is swollen or irritated, usually from viral infection. The resulting chest pain usually feels like a sharp, stabbing pain in either the center or the left side of your chest. In some patients, though, the pain is more of a dull pressure that spreads to the jaw and/or left arm. This pain can worsen with breathing or movement. Some of the symptoms of pericarditis look a lot like those of a heart attack:  Shortness of breath Heart palpitations Low-grade fever Fatigue or nausea Cough Swollen legs or abdomen Though pericarditis is often mild and resolves on its own, it's difficult to distinguish between its symptoms and those of a heart attack. It can also develop into more severe cases that can require surgery to relieve the symptoms. You need immediate supervision and diagnostic tests to find out what's actually causing the pain.  Call emergency services or ask someone to take you to the nearest emergency room. Just like with heart attacks, early treatment is the best way to prevent the condition from worsening. The pericardium has two layers of tissue that rub together when inflamed, causing the chest pain. By sitting in this position, you can reduce the tissue friction and its resulting pain while waiting for medical attention. Taking a non-steroidal anti-inflammatory drug like aspirin or ibuprofen will reduce the tissue inflammation. This, in turn, reduces the friction between the two layers of the pericardium and eases your chest pain.  Consult your doctor before taking these medications. With physician approval, take these medications three times a day with food. You should take a total of two to four grams of Aspirin per day or 1200 to 1800 mg of ibuprofen per day. Pericarditis is usually the result of a viral infection. You can treat it like the common cold to speed up your recover and eliminate the pain quickly. Rest and sleep will help your immune system function more efficiently, speeding up the healing process.

Summary:
Learn the symptoms of pericarditis. Seek immediate medical attention. Ease the pain by sitting up and leaning forward. Take aspirin or ibuprofen. Get plenty of rest.