Your doctor will examine you and take your medical history. To confirm the diagnosis and determine how severe any damage is, your doctor will order tests and scans. 

• chest X-ray
• CT scan
• electrocardiogram (a recording of the heart's electrical activity, also called an EKG)
• measurement of the level of oxygen in your blood (arterial blood gas)
• lung scan (using tracers to get pictures of the flow of blood in your lungs)
• ultrasound scan of your legs to look for clots

You usually need to be in the hospital. Your treatment depends on the results of lab tests, how sick you are, and where the blood clot comes from. Most pulmonary embolisms can be treated with blood thinners. These medicines stop the clot from getting bigger and allow your body to try to dissolve the blood clot. They also stop more clots from forming. You will start taking a blood thinner by IV or by injection in the hospital. You will continue taking a different kind of blood thinner, usually a pill, after you leave.

You may need another drug that works quickly to dissolve the blood clot. Because this medicine makes it much harder for your blood to clot, you must be watched carefully for too much bleeding during your treatment.

If you are very ill, surgery to remove the clot from your artery may be your only chance for survival. The surgery will improve blood flow through your lungs.

If you keep having more clots, you may have surgery to put a small plastic filter in the large abdominal vein that returns blood to the heart. The filter can trap blood clots and prevent them from reaching your lungs.