A blood clot in the leg, also known as deep vein thrombosis (DVT), can cause a range of symptoms. Detecting a blood clot early is important, as it can help prevent complications like pulmonary embolism. Here is an overview of the common signs and symptoms to look out for if you suspect a blood clot in the leg.
Pain
One of the most common symptoms of a blood clot in the leg is pain. This pain often starts in the calf muscle and feels like a charley horse or muscle cramp. The pain may only occur when walking or moving the leg. It can range from mild to quite severe. As the clot gets bigger, the pain often spreads to the thigh or the entire leg.
Swelling
Leg swelling, or edema, frequently occurs with a DVT. The swelling often starts in the ankle and foot area. As the blood clot worsens, swelling can spread up the leg. The skin over the area of swelling may appear tight, shiny, warm, and reddened.
Skin discoloration
An area of skin redness or bluish discoloration may appear where a blood clot is located. This results from a buildup of deoxygenated blood. The discolored area usually occurs in the calf or thigh. Skin discoloration from a blood clot can sometimes take on a spidery or net-like pattern.
Leg warmness
People with a DVT often report a feeling of unusual warmth in the leg. This occurs because of increased blood flow around the blood clot. Areas just past the actual clot location experience faster blood flow as the body tries to compensate for the blockage.
Leg weakness
Some people with a DVT experience leg muscle weakness. This symptom often comes on gradually. Weakness results from restricted blood flow and oxygen delivery to the muscles. People may notice increased leg fatigue with activity or trouble moving the leg.
Leg heaviness
A feeling of heaviness or tension in the leg can occur with a DVT. This symptom develops from obstruction to blood drainage and swelling. Heaviness usually starts in the calf and can spread upwards. Moving the leg tends to intensify the uncomfortable sensation.
Visible surface veins
Sometimes a blood clot causes superficial leg veins to abnormally dilate and become more visible. Distended surface veins result from increased blood pressure in these veins. This happens because the clot obstructs outflow from the deeper veins.
Cramping
Muscle cramping or charley horses are fairly common when someone has a DVT. These painful spasms often occur in the calf or foot and may persist. It’s thought that reduced blood flow triggers the involuntary muscle contractions.
Tingling or numbness
Some people with a DVT experience a tingling, pins and needles, or numb sensation in the leg or foot. This results from irritation of nerve fibers from swelling and inflammation. Pressure on nerve fibers from the blood clot can also contribute to numbness.
Leg itching
An itchy feeling in the leg or calf is another potential symptom of a blood clot. Researchers believe swelling and inflammation from the DVT irritates sensory nerve fibers in the skin, triggering sensations of itching.
Knee pain
For blood clots located behind the knee area, a person may feel pain in the back of the knee. There may also be calf stiffness or tightness. Knee pain or swelling should not be ignored as it can indicate a dangerous clot.
Skin redness
Skin redness may appear in the area of a blood clot due to increased blood flow. When a vein is blocked, nearby smaller veins will dilate to compensate. This brings more blood to the surface veins, creating distinct reddish patches.
Calf tenderness
DVT often causes tenderness and soreness in the calf muscle. Even light pressure or touch to the calf may elicit discomfort. Calf tenderness usually indicates inflammation related to a clot in the deep calf veins.
Leg ulcer
An ulcer is a breakdown in the skin that appears as an open sore. Leg ulcers can arise from the skin damage caused by long-term swelling. Large blood clots that obstruct blood flow significantly increase the risk of leg ulcers.
Altered gait
Someone with a DVT may develop an altered gait or limp. This results from calf muscle tightness and tenderness. People may avoid bearing full weight on the affected leg due to pain and muscle weakness.
Complications
A DVT can sometimes lead to potentially life-threatening complications. Recognizing these complications early is critical.
Pulmonary embolism
A pulmonary embolism is a very serious complication where the blood clot dislodges from the leg and travels to the lungs. Warning signs include sudden chest pain, cough, dizziness, rapid heart rate, or shortness of breath.
Post-thrombotic syndrome
Post-thrombotic syndrome involves long-term damage to the leg veins from the DVT. It can cause chronic leg pain, swelling, varicose veins, and leg ulcers. Proper treatment lowers the risk of developing this syndrome.
Stroke
Rarely, part of the blood clot can break off and travel to the brain, causing a stroke. Symptoms include confusion, trouble speaking, and numbness or weakness on one side of the body.
When to see a doctor
It’s important to seek prompt medical attention if you have any signs or symptoms that suggest a potential blood clot in the leg. Early treatment is vital.
See a doctor right away if you notice:
- Sudden onset leg pain and/or swelling
- Warmth, redness, or discoloration in the leg
- Rapid breathing or chest pain
- Calf tenderness
Call 911 or emergency medical help if you experience:
- Sudden shortness of breath
- Coughing up blood
- Fainting
- Loss of consciousness
Causes
Blood clots develop from a complex interplay of vascular, mechanical, and chemical factors in the body. Some of the key contributors to DVT formation include:
- Slowed blood flow in the veins
- Blood vessel wall damage
- Increased tendency for blood clotting
- Chronic inflammation
Risk factors
A number of factors or conditions can increase a person’s risk of developing a DVT. These include:
| Risk factor | Description |
|---|---|
| Inactivity | Lack of movement (bed rest, sitting for travel) |
| Surgery | Major surgery that may involve leg veins |
| Trauma | Injury to blood vessels from fractures |
| Pregnancy | Increased blood-clotting factors during pregnancy |
| Birth control pills | Estrogen increases clotting risk |
| Genetics | Inherited clotting disorders |
| Cancer | Cancer and chemotherapy increase clotting |
| Heart failure | Reduced blood flow out of the veins |
| Obesity | Increases inflammation and slows blood flow |
| Smoking | Damages blood vessels |
Diagnosis
If a DVT is suspected after evaluating symptoms, the doctor will likely order imaging tests to confirm the diagnosis and determine the clot size and location. Common diagnostic tools include:
- Duplex ultrasound – This uses sound waves to look for clots in the veins. It’s the main test used to diagnose DVT.
- Venography – A dye is injected into a foot vein while x-rays are taken. Blockages from clots are visible.
- MRI – A magnetic resonance imaging scan can show blood flow in veins. It may detect clots.
- CT scan – A computed tomography scan provides images of the veins and can reveal blood clots.
- Blood tests – These check for signs of increased blood clotting ability.
Treatment
Prompt treatment for DVT helps prevent the clot from growing and traveling to the lungs. Treatment options may include:
- Anticoagulants – Blood thinning medication stops clot extension. Heparin or warfarin are often used.
- Thrombolytics – These drugs dissolve blood clots over time.
- Compression stockings – Stockings improve blood flow and decrease swelling.
- Filter placement – A filter implanted in the large vein stops clots from reaching lungs.
- Leg elevation – Keeping the leg raised above heart level aids blood drainage.
- Early walking – Light activity promotes blood flow out of the leg veins.
Treatment typically continues for at least 3 to 6 months after a DVT. Long-term anticoagulation may be necessary in some people.
Prevention
Various strategies can help prevent the formation of dangerous blood clots in the leg veins:
- Stay active – Regular exercise promotes healthy blood flow in the legs.
- Lose weight – Obesity is a significant risk factor for DVT.
- Quit smoking – Smoking damages blood vessels.
- Medical stockings – Compression stockings boost leg vein circulation.
- Blood thinners – Anticoagulant medication may be used preventively in high-risk settings like hospitalization.
- Leg exercises – Simple leg flexing exercises help blood flow during periods of inactivity like long distance travel.
Conclusion
A blood clot in the leg can cause various symptoms like pain, swelling, warmth, and discoloration in the leg. It is vital to seek prompt medical care if a DVT is suspected. With early diagnosis and treatment, complications like pulmonary embolism can often be prevented. Maintaining good leg health through regular activity, exercise, weight management, and proper medical care can all help lower the risk of dangerous blood clots.