How Serious Is a Blood Clot in the Lungs?

The signs and symptoms of pulmonary embolism differ depending on the size of the clot, extent of lung involvement, and underlying medical conditions.

A blood clot is a solid or semisolid clump of blood. When the tissues of our body are injured, excessive blood loss is prevented by the clotting of blood. When a blood clot occurs inside the blood vessels it may lead to serious medical conditions. When a blood clot occurs inside the arteries to the lungs, the condition is called pulmonary embolism (PE). The terms ‘embolus’ (plural: emboli) and ‘embolism’ refer to a blood clot or a part of a blood clot that forms at one site in the body and travels to another site. Pulmonary embolism is a condition in which this traveling clot lodges itself in the arteries of the lungs.

Pulmonary embolism can be caused by many factors:

• Surgery, especially surgery on the abdomen, hip, and knees
• Bone fracture, especially long bone fractures such as of the thigh bone (femur)
• A long period of confinement to the bed or a wheelchair
• Prolonged hospitalization
• Cancer and chemotherapy
• Pregnancy and the first six weeks after delivery
• Heart diseases
• Stroke
• Estrogen-containing birth control pills
• Hormone replacement therapy containing estrogen
• Being obese or overweight
• Long hours of sitting, such as on a long air flight
• Smoking
• Family history of blood clots

The signs and symptoms of pulmonary embolism differ depending on:

• Size of the clot 
• The extent of lung involvement
• Underlying medical conditions

Common signs and symptoms of pulmonary embolism are:

• Shortness of breath.
• Chest pain, which may get worse while breathing.
• Cough, which may be associated with coughing up blood.
• Pain in the shoulder, arm, neck, or back.
• Pale or bluish lips and nails.
• Excessive sweating.
• Leg pain or swelling.
• Lightheadedness, dizziness, or passing out.
• Palpitations (feeling of racing heartbeat).
• Wheezing (noisy breathing).
• Anxiousness.

Early treatment of pulmonary embolism is important to prevent serious complications. Treatment aims at preventing:

• An increase in the size of the blood clot
• The formation of new clots

Treatment options include:

• Anticoagulation medicines (blood thinners): They are the most common treatment for a blood clot in the lungs. Although blood thinners do not make your blood thin. They slow the process of new clots forming and prevent the already formed ones from getting bigger. Blood thinners include:
  • Unfractionated heparin (UFH)
  • Low-molecular-weight heparin (LMWH)
  • Warfarin
  • Direct oral anticoagulant (DOAC) medications
• Thrombolytic therapy (“the clot busters” or “clot dissolvers”) to dissolve the existing clots.
• Surgery may be needed to remove a very large, life-threatening clot.
• Compression stockings may be useful to prevent the recurrence of pulmonary embolism, as most of the clots in the lungs originate in the legs. 
• A vena cava filter may be surgically placed in a large vein of the abdomen called the vena cava. It can ‘filter out’ or catch blood clots from the legs before they reach the lungs.
• Management of risk factors ( cessation of smoking, weight control, regular exercise).
• Suitable attention must be given to reduce the risk of bleeding while on anticoagulants. The doctor may advise avoiding certain foods, alcohol, or some over-the-counter medications (such as aspirin and sleeping pills). 
• People on blood thinners should not overexert themselves during exercises. 

Although a clot in the lung may be a life-threatening condition, with appropriate treatment and lifestyle modifications that reduce the risk factors, most people live well.

Some of the complications of pulmonary embolism are:

• Disorders of heart rhythm (arrhythmias)
• Shock
• Heart failure
• Pleural effusion (collection of fluid around the lungs)
• Pulmonary infarction (the death of lung tissue)
• Pulmonary hypertension (high blood pressure in the blood vessels of the lungs)
• Sudden cardiac death

As treatment of pulmonary embolism involves using anticoagulants, there can be anticoagulant related complications also. These include:

• Excessive bleeding 
• Blood in vomit or vomit that looks like coffee grounds
• Blood in stool or black, tarry stools
• Headache
• Sudden vision changes
• Sudden loss of strength in any of the limbs
• Confusion
• Memory loss
• Fainting