What are the signs and symptoms of pulmonary embolism?
The most common symptoms of a pulmonary embolus are:
- Chest pain: The pain is classically described as pleurtic, a sharp pain that worsens when taking a deep breath.
- A cough that may produce bloody sputum (hemoptysis)
- Shortness of breath: The person may have difficulty catching their breath at rest, and the shortness of breath often worsens with activity.
The patient may have stable vital signs (blood pressure, heart rate, respiratory rate, and oxygen saturation), but depending upon the amount of blood clot in the lung and how much lung tissue is affected, the vital signs may be abnormal.
Classic signs of a pulmonary embolus are associated with abnormal vital signs. Depending on the amount of blood clot (clot burden or clot load), the following may occur:
- Elevated heart rate: tachycardia (tachy=fast + cardia=heart)
- Elevated respiratory (breathing) rate: tachypnea (tachy=fast + pnea= breathing)
- Bluish discoloration of skin and mucous membranes (cyanosis), due to decreased oxygen saturation (red blood cells that do not have oxygen molecules attached to them)
- Decreased blood pressure: hypotension (hypo=low + tension=pressure)
The condition progresses as follows:
- The heart rate and respiratory rate may elevate as the body tries to compensate for less oxygen transfer in the lung. Breathing and heart rate increase to help circulate the blood throughout the body more quickly, so that the available oxygen can be distributed as best as possible to the body's organs and tissues.
- This may lead to weakness and lightheadedness as the body's organs are deprived of the necessary oxygen to function.
- If the blood clot is large enough, it can block blood from exiting the right side of the heart, thus preventing blood from entering the lungs.
- No blood enters the left side of the heart to pump blood throughout the rest of the body. This can result in shock (circulatory collapse) and sudden death.
Up to 25% of patients with pulmonary embolus may experience sudden death, in which the patient collapses, stops breathing, and their heart stops beating (cardiac arrest) without prior symptoms. Pulmonary embolus is the second leading cause of sudden death, behind coronary artery disease.