This is a medical question of type : exams and tests 
 How to diagnose Pericarditis ? 
 Your doctor will diagnose pericarditis based on your medical history, a physical exam, and the results from tests.
                
Specialists Involved
                
Primary care doctorssuch as a family doctor, internist, or pediatricianoften diagnose and treat pericarditis. Other types of doctors also may be involved, such as a cardiologist, pediatric cardiologist, and an infectious disease specialist.
                
A cardiologist treats adults who have heart problems. A pediatric cardiologist treats children who have heart problems. An infectious disease specialist treats people who have infections.
                
Medical History
                
Your doctor may ask whether you:
                
Have had a recent respiratory infection or flu-like illness
                
Have had a recent heart attack or injury to your chest
                
Have any other medical conditions
                
Your doctor also may ask about your symptoms. If you have chest pain, he or she will ask you to describe how it feels, where it's located, and whether it's worse when you lie down, breathe, or cough.
                
Physical Exam
                
When the pericardium (the sac around your heart) is inflamed, the amount of fluid between its two layers of tissue increases. As part of the exam, your doctor will look for signs of excess fluid in your chest.
                
A common sign is the pericardial rub. This is the sound of the pericardium rubbing against the outer layer of your heart. Your doctor will place a stethoscope on your chest to listen for this sound.
                
Your doctor may hear other chest sounds that are signs of fluid in the pericardium (pericardial effusion) or the lungs (pleural effusion). These are more severe problems related to pericarditis.
                
Diagnostic Tests
                
Your doctor may recommend one or more tests to diagnose your condition and show how severe it is. The most common tests are:
                
EKG (electrocardiogram). This simple test detects and records your heart's electrical activity. Certain EKG results suggest pericarditis.
                
Chest x ray. A chest x ray creates pictures of the structures inside your chest, such as your heart, lungs, and blood vessels. The pictures can show whether you have an enlarged heart. This is a sign of excess fluid in your pericardium.
                
Echocardiography. This painless test uses sound waves to create pictures of your heart. The pictures show the size and shape of your heart and how well your heart is working. This test can show whether fluid has built up in the pericardium.
                
Cardiac CT (computed tomography (to-MOG-rah-fee)). This is a type of x ray that takes a clear, detailed picture of your heart and pericardium. A cardiac CT helps rule out other causes of chest pain.
                
Cardiac MRI (magnetic resonance imaging). This test uses powerful magnets and radio waves to create detailed pictures of your organs and tissues. A cardiac MRI can show changes in the pericardium.
                
Your doctor also may recommend blood tests. These tests can help your doctor find out whether you've had a heart attack, the cause of your pericarditis, and how inflamed your pericardium is.