Blood clots can be dangerous if left untreated. Knowing the signs and symptoms of a blood clot is important for getting prompt medical care. This article provides an overview of blood clots, their symptoms, risk factors, and treatment options.
What is a blood clot?
A blood clot, also called a thrombus, forms when blood thickens and clumps together. Clots are a normal part of the body’s healing process when you have an injury. They stop bleeding by plugging damaged blood vessels. However, clots can also form inside healthy blood vessels, which is problematic. Clots that form inside arteries or veins without an injury can partially or completely block blood flow. This can damage tissues and organs and be life-threatening.
Types of Blood Clots
There are two main types of blood clots:
- Arterial clots – Clots that form inside arteries are called arterial or arterial thromboembolism. They often form in people with atherosclerosis (fatty deposits in arteries). Pieces of an arterial clot can break off and travel to other organs, blocking blood flow and causing damage. An arterial clot is often called an embolism.
- Venous clots – Clots in a vein are known as venous or deep vein thrombosis (DVT). DVT typically occurs in leg veins but can form in other parts of the body. Part of the clot can break off and travel to the lungs, causing a pulmonary embolism (PE). DVT and PE are known collectively as venous thromboembolism (VTE).
Signs and Symptoms of a Blood Clot
The signs and symptoms of a blood clot depend on the location. Some clots may cause no symptoms initially. Symptoms that can occur include:
Arterial Clot Symptoms
- Sudden confusion, slurred speech, dizziness, loss of balance or coordination, severe headache, blurred vision, or weakness on one side of the body (signs of stroke)
- Chest pain, shortness of breath, sweating, nausea, vomiting, lightheadedness (signs of heart attack)
- Sudden pain, coldness, paleness, numbness or weakness in a leg or arm (signs of clot in limb artery)
- Severe abdominal pain, back pain, vomiting, fever (signs of clot in digestive tract artery)
- Severe abdominal pain, dizziness, nausea, vomiting (signs of clot in liver artery)
- Severe abdominal pain, bloody vomit or stool (signs of clot in spleen artery)
- Severe pain behind one eye, nausea, vomiting, headache, blurred vision (signs of clot in eye artery)
Venous Clot Symptoms
- Swelling in one arm or leg
- Leg pain or tenderness
- Leg warm to the touch
- Leg redness or discoloration
- Leg cramping
- Chest pain that worsens with deep breathing
- Rapid breathing
- Cough, possibly with blood-tinged mucus
- Rapid heart rate
- Fever and sweating
- Lightheadedness or passing out
Risk Factors for Blood Clots
Certain factors raise the risk of developing a blood clot. Understanding personal risk factors allows people to take preventive measures where possible.
Risk Factors for Clots Include:
- Older age – Risk increases over age 40
- Obesity
- Smoking
- Family history of blood clots
- Inactivity or prolonged sitting
- Pregnancy and up to 6 weeks after giving birth
- Oral contraceptives and estrogen therapy
- Cancer and cancer treatment
- Some inherited blood disorders
- Major surgery or trauma
- Broken bone or severe muscle injury
- Hospitalization and prolonged bed rest
- Travel involving prolonged immobility
- Some types of heart disease
- Blood vessel inflammation (vasculitis)
Diagnosing a Blood Clot
If symptoms suggest a possible blood clot, prompt medical evaluation is essential. Diagnostic tests used to detect clots include:
Tests for Blood Clots
- D-dimer blood test – Measures breakdown products of a clot. Levels are elevated with clots.
- Ultrasound – Uses sound waves to detect clots in limbs, chest, or abdomen.
- Venogram – X-ray of veins using injected dye to visualize clots.
- CT scan – Cross-sectional X-rays create images of the body to locate clots.
- MRI – Uses magnetic fields to produce detailed images that can show clots.
- Ventilation-perfusion (V/Q) scan – Nuclear imaging of the lungs to check for PE.
- Angiography – Dye is injected into the blood while X-ray images are captured.
- Surgical vessel exploration – Visual inspection of blood vessels during surgery.
The type of test used depends on the suspected location of the clot. Prompt diagnosis is key because the longer a clot remains, the greater the risks of serious complications.
Treating Blood Clots
Treatment focuses on preventing the clot from getting bigger, preventing additional clots, reducing symptoms, and minimizing complications. Options may include:
Blood Clot Treatments
- Anticoagulants (blood thinners) – Medications like heparin or warfarin. They prevent clot enlargement and new clots.
- Thrombolytics (clot busters) – Medications like tPA that dissolve clots.
- Thrombectomy – A catheter inserted into a blood vessel to remove a clot.
- Filter placement – A filter implanted in the vena cava vein to prevent PE.
- Compression stockings – Reduce swelling and improve blood flow.
- Leg elevation – Decreases swelling and improves venous flow.
The length of treatment depends on the cause and location of the clot. Short term treatment may last several weeks to months while lifelong treatment is sometimes necessary. Close monitoring is required to ensure adequate clot prevention with minimal bleeding risk from therapy.
Preventing Blood Clots
Prevention is ideal, especially if you have clotting risk factors. Preventive measures include:
Ways to Reduce Clotting Risk
- Lose excess weight
- Exercise regularly
- Avoid long periods of inactivity
- Stay hydrated
- Avoid crossing legs for long periods
- Elevate legs when possible
- Wear compression stockings if recommended
- Discuss hormone therapy risks with your doctor
- Maintain optimal blood pressure and cholesterol
- Stop smoking
Additional preventive measures before surgery may include:
- Stopping birth control pills
- Beginning bridging anticoagulation therapy
- Wearing compression stockings
- Using a foot/leg pump device to improve blood flow
When traveling for a prolonged time:
- Get up and walk periodically on flights
- Perform foot and leg exercises while seated
- Stay hydrated
- Consider graduated compression stockings
Key Points
Some key points on recognizing and preventing blood clots:
- Blood clots can occur in arteries or veins with varying signs and symptoms.
- Many factors can increase clotting risk including age, inactivity, certain medications or medical conditions, and surgery.
- Prompt diagnosis is important to avoid complications like stroke, pulmonary embolism, or death.
- Anticoagulant medications are usually the mainstay of blood clot treatment.
- Prevention through lifestyle measures and awareness of personal risk factors is the best approach.
The Bottom Line
Blood clots can be life threatening if not promptly diagnosed and treated. Knowing the signs and symptoms, as well as your potential risk factors, allows you to take action quickly if a clot is suspected. Blood clots can often be prevented through simple lifestyle measures and working with your healthcare providers to control modifiable risk factors.
Type of Blood Clot | Common Locations | Symptoms |
---|---|---|
Arterial (Arterial Thromboembolism) | Heart, Brain, Limbs, Organs supplied by abdominal arteries | Chest pain, limb pain, severe headache, confusion, weakness, speech problems, abdominal pain, nausea/vomiting, shortness of breath |
Venous (Deep Vein Thrombosis) | Legs, arms, pelvis, intestines | Leg swelling/pain/warmth/redness, chest pain with breathing, cough, rapid heart rate, lightheadedness |
Diagnostic Test | Description |
---|---|
D-dimer blood test | Measures breakdown products of a clot |
Ultrasound | Uses sound waves to visualize clots in limbs, chest, abdomen |
Venogram | X-ray using injected dye to visualize clots in veins |
CT scan | Cross-sectional X-rays create images of clots |
MRI scan | Magnetic fields produce images that show clots |
V/Q lung scan | Nuclear imaging to check for pulmonary embolism |
Angiography | X-ray images are captured after dye injection |
Vessel exploration | Visual inspection for clots during surgery |