Blood clots can cause a fever, which is often a sign of the body’s response to the clot itself or, less commonly, an infection. This fever, especially when combined with other symptoms, can indicate a significant medical event requiring attention.
How Blood Clots Trigger Fever
The presence of a blood clot, such as in deep vein thrombosis (DVT) or pulmonary embolism (PE), can trigger the body’s inflammatory response. The immune system recognizes the clot as an abnormal presence, activating defense mechanisms. This involves releasing signaling proteins called cytokines. These cytokines travel through the bloodstream to the hypothalamus, the part of the brain that regulates body temperature. The hypothalamus then raises the body’s set point, leading to a fever.
In some situations, a blood clot might also be associated with an infection, leading to a fever. This can occur if a clot forms in response to an existing infection, or if the clot itself becomes infected. The body’s fight against bacterial or fungal presence then results in an elevated body temperature. While infection can cause fever, the inflammatory response to the clot’s presence is a more common reason for fever.
Recognizing Other Symptoms
Beyond fever, blood clots often present with other symptoms depending on their location. If a clot forms in a deep vein, commonly in the legs, it is known as deep vein thrombosis (DVT). Symptoms of DVT in the affected limb can include throbbing pain, swelling, and tenderness, often in the calf or thigh. The skin around the clot may also appear reddish or discolored and feel warm.
If a blood clot travels from a deep vein to the lungs, it becomes a pulmonary embolism (PE). Symptoms of PE include sudden shortness of breath, which may worsen with activity or deep breaths. Chest pain is common, often described as sharp and increasing with inhalation. Other signs include a rapid heartbeat and a cough, sometimes producing bloody mucus.
When to Seek Medical Attention
Any suspected blood clot warrants prompt medical evaluation. If a fever is present alongside symptoms of a deep vein thrombosis, such as pain, swelling, or warmth in a limb, medical attention is important. Early diagnosis and treatment can prevent the clot from growing or traveling.
Immediate emergency care is necessary if symptoms suggest a pulmonary embolism. Urgent signs include sudden shortness of breath, severe chest pain, or fainting. A rapid heart rate or coughing up blood also indicates a medical emergency. Timely diagnosis and treatment are important to reduce life-threatening risks.