A blood clot in the leg can be life-threatening if it travels through the bloodstream and becomes lodged in the lungs. This extreme complication can cause a pulmonary embolism, but even before a clot reaches this severity, it can cause a range of potentially dangerous symptoms.

Inflammation

Blood clots can cause unexplained swelling. The density of the bone and tissue in this part of the body makes it difficult to break down or absorb clots naturally. Inflammation or swelling of the calf, ankle, or upper leg may indicate a blood clot, especially if the usual home treatments for swelling, such as cold and hot compresses, fail to alleviate this symptom.

Redness of Skin

Blood clots in deep veins of the legs may cause patches of redness or darkening of the overlying skin. These patches may expand over time for no evident reason. Following an injury or surgical procedure, any redness on the skin that does not go away as expected should be evaluated by a physician.

Warm Skin

Blood clots often cause localized changes in temperature, with the skin surrounding the clot becoming warm to the touch. The affected skin may seem to radiate heat or even tingle and throb. If cold compresses do not reduce this heat or sensation and the symptom persists, see a doctor.

Tenderness

In some cases, the skin surrounding the clot may become sore, painful, or tender to the touch. Even a clot in a vein deep may cause tenderness if it is relatively large. In addition to direct pain, this symptom often requires people to rely on their other leg more to relieve the pain, which can lead to muscle and joint strain.

Increased Heart Rate

When a blood clot in the leg grows, the body attempts to eradicate it. Vital organs work harder, leading to an increase in heart rate. A higher heart rate may produce symptoms of its own, such as breathlessness and chest pains. An elevated heart rate that cannot be linked to physical exertion or other known conditions should be evaluated by a doctor.

Fever

When a blood clot detaches and enters the bloodstream, some people develop a low-grade fever that may also prompt chills, shivering, sweating, headaches, weakness, dehydration, fatigue, and body aches. If the temperature shoots very high, individuals may experience mood changes, confusion, and other psychological anomalies.

Distended Veins

Distension of surface veins on the skin surrounding the affected area sometimes indicates the presence of a clot. If the clot becomes large and the surrounding blood vessels are compressed, it is a cause for concern. Varicose veins also increase the risk of blood clots in the deep veins of the leg.

Fainting

If the blood clot moves to the lungs, respiratory symptoms may occur. When the circulation of oxygenated blood to the brain is compromised, you may experience dizziness and fainting spells. Typically, people do not associate unexplained fainting with blood clots, and this can lead to misdiagnosis. Anyone experiencing frequent dizziness or fainting spells should consult a doctor.

Fatigue

When a blood clot develops in the legs, the body’s natural defense mechanisms work overtime to eliminate it. When the body’s energy and resources are focused on this task, weakness, and fatigue develop. People with blood clots may find themselves feeling tired without exertion, even after sleeping.

No Symptoms

In about half the cases of blood clots in the leg, no symptoms appear until the clot detaches and becomes lodged in the lungs. At this time, there could be a limited period during which doctors can treat or remove the clot before it begins causing serious complications, such as pulmonary embolism. Signs and symptoms of pulmonary embolism include difficulty breathing, faster or irregular heartbeats, chest discomfort, and very low blood pressure. It is vital to speak to a doctor as soon as multiple symptoms appear, however unrelated they may seem.