Pulmonary embolism  

Overview  

A pulmonary embolism refers to a situation in which a blood clot obstructs an artery within the lung, leading to a cessation of blood circulation. Typically, these blood clots originate in the deep veins of the leg and then migrate to the lung. In rarer cases, these clots might form in veins located in other parts of the body. When blood clots manifest in one or multiple deep veins, this is termed deep vein thrombosis (DVT). 

Because these clots can impede the blood flow to the lungs, a pulmonary embolism has the potential to be life–threatening. Nevertheless, swift and appropriate treatment significantly reduces the likelihood of fatality. Taking preventive measures to avoid blood clot formation in the legs plays a pivotal role in safeguarding against the occurrence of a pulmonary embolism.  

Symptoms  

The symptoms of pulmonary embolism can vary significantly based on factors like the extent of lung involvement, clot size, and any preexisting lung or heart conditions. Typical signs encompass: 

• Sudden onset of shortness of breath: Breathing difficulties can occur even while at rest and intensify during physical exertion. 
• Chest discomfort: Resembling a potential heart attack, this sharp pain is often experienced during deep inhalation. It might hinder your ability to take full breaths and could be triggered by coughing, bending, or leaning forward. 
• Episodes of fainting: In some cases, a sudden drop in heart rate or blood pressure, known as syncope, might lead to loss of consciousness. 

Additional symptoms that can manifest alongside pulmonary embolism include: 

• Coughing, potentially accompanied by mucus tinged with blood or streaked with blood. 
• Rapid or irregular heartbeat, also known as palpitations. 
• Feelings of lightheadedness or dizziness. 
• Profuse sweating. 
• Fever. 
• Pain or swelling in the leg, often at the back of the lower leg. 
• Skin that is clammy or discolored, a condition referred to as cyanosis.

A pulmonary embolism has the potential to be life–threatening. If you encounter unexpected shortness of breath, chest pain, or fainting, it is crucial to seek immediate medical assistance.   

Causes   

A pulmonary embolism happens when a blood clot or other material blocks a lung artery, impeding blood flow. These clots often originate from leg veins, causing deep vein thrombosis. Multiple clots can compound the issue, leading to lung tissue damage, known as pulmonary infarction, hampering oxygen delivery to the body. Occasionally, vessel blockages result from sources like fat from broken bones, tumor fragments, or air bubbles.   

Risk factors   

Factors that can increase the risk of blood clots leading to a pulmonary embolism include: 

1. 1. Personal or Family History: If you or your family members have had blood clots or pulmonary embolisms in the past, your risk is higher.

2. 2. Medical Conditions and Treatments:

• Heart Disease: Conditions like heart failure make clot formation more likely. 
• Cancer: Certain cancers, especially those that have spread, along with chemotherapy, increase clot risk. Personal/family history of breast cancer and taking specific medications also raise risk. 
• Surgery: Major surgeries, such as joint replacements, can cause clots. Preventative medication might be given. 
• Clotting Disorders: Inherited or medical conditions affecting blood can increase clot risk. 
• COVID–19: Severe COVID–19 symptoms elevate the risk of pulmonary embolism. 

3. 3. Extended Inactivity:

• Bed Rest: Prolonged bed rest after surgery or illness slows leg blood flow, promoting clot formation. 
• Long Trips: Sitting for extended periods during travel can slow leg blood flow and increase clot risk. 

4. 4. Other Risk Factors:

• Smoking: Smoking, especially when combined with other risk factors, increases clot risk. 
• Excess Weight: Being overweight, especially with other risk factors, heightens clot risk. 
• Estrogen: Hormone therapies containing estrogen, particularly when combined with smoking or overweight, increase clotting factors. 

Pregnancy: Pressure from the growing baby can slow blood flow in veins, leading to clot formation.