A blood clot is a gel-like mass of blood cells and proteins that forms within blood vessels. Clots naturally develop as a protective mechanism to stop bleeding after an injury. Platelets and clotting factors work together to create this mass. Once bleeding stops and the vessel heals, the body typically breaks down and removes the clot. However, clots can sometimes form inappropriately or fail to dissolve, potentially leading to health concerns.
What Happens When a Clot Dislodges
When a blood clot breaks away from its original location, it becomes an embolus. This dislodged clot does not cause bleeding at its origin. The concern is not bleeding from the dislodged clot, but its travel through the bloodstream. As the embolus moves, it can lodge in a narrower blood vessel, obstructing blood flow to organs or tissues. This blockage, called an embolism, can deprive the affected area of oxygen and nutrients, leading to damage.
Potential Destinations and Their Impact
A dislodged blood clot can travel to various parts of the body, leading to serious medical conditions depending on where it settles and blocks blood flow.
Pulmonary Embolism (PE)
A common destination for a dislodged clot is the lungs, resulting in a pulmonary embolism. This occurs when a clot, often from a deep vein in the leg (DVT), travels to an artery in the lungs and blocks it. This blockage restricts blood flow to parts of the lung, which can damage lung tissue and lower oxygen levels throughout the body. A large pulmonary embolism or multiple clots can severely strain the heart, as it must work harder to pump blood through the obstructed vessels.
Stroke
Another destination for a traveling clot is the brain, leading to an ischemic stroke. An ischemic stroke happens when a blood clot blocks an artery supplying blood to the brain, cutting off oxygen and nutrients to brain cells. Brain cells can begin to die within minutes without adequate blood flow, causing lasting brain damage. While some strokes are caused by clots forming directly in brain arteries, others occur when a clot from elsewhere, such as the heart or neck arteries, travels to the brain.
Heart Attack
Although less common for clots dislodging from distant sites, a heart attack can also involve blood clots. A heart attack occurs when blood flow to the heart muscle is blocked. This often happens when plaque in a coronary artery ruptures, and a blood clot forms at the site, completely obstructing the artery. In some instances, a clot that forms in the heart can dislodge and block a coronary artery, leading to a heart attack.
Peripheral Artery Occlusion
Dislodged clots can also travel to arteries in the limbs, most frequently the legs, causing acute peripheral artery occlusion. This condition involves a sudden and severe blockage of a peripheral artery, interrupting blood flow to the limb. Without prompt restoration of blood flow, the affected tissues do not receive enough oxygen, which can lead to severe pain, numbness, coldness, and potential tissue death. Prolonged lack of blood flow can result in permanent damage, and in severe cases, may necessitate amputation.
Identifying Symptoms of a Blockage
Recognizing symptoms of a blood clot blockage is important for timely medical attention. The specific signs depend on where the clot has lodged in the body.
For a pulmonary embolism, symptoms often include sudden shortness of breath, which may occur at rest and worsen with activity. Chest pain is common, often described as sharp and worsening with deep breaths or coughing. Other indicators can be a rapid heartbeat, lightheadedness, or a cough that sometimes produces bloody mucus.
Symptoms of a stroke are often sudden and can be remembered using the FAST acronym:
- Face drooping: One side of the face might droop or feel numb.
- Arm weakness: One arm may feel weak or numb, making it difficult to raise both arms equally.
- Speech difficulty: Slurred speech or trouble understanding what others are saying.
- Time to call emergency services immediately if any of these symptoms appear.
Other stroke symptoms can include sudden numbness or weakness on one side of the body, blurred vision, confusion, or a sudden severe headache.
In cases of acute peripheral artery occlusion, symptoms in the affected limb, typically a leg, appear suddenly. These include severe pain, a pale or bluish appearance of the skin, and a cold sensation in the limb. Numbness or a “pins and needles” feeling, along with a weak or absent pulse in the limb below the blockage, are also common.
When to Seek Emergency Care
Any suspicion of a dislodged blood clot or sudden severe symptoms requires immediate emergency medical attention. Prompt treatment is important to minimize organ damage. If you experience sudden shortness of breath, severe chest pain, or symptoms consistent with a stroke or acute limb blockage, contact emergency services right away. Call 911 or your local emergency number rather than driving yourself or someone else to the hospital. These situations are medical emergencies that require rapid diagnosis and intervention by healthcare professionals.