Understanding Blood Clots: Symptoms, Causes, Types, and Who May Be at Risk
Blood clots are a natural and important part of the body’s healing process—but when they form at the wrong time or in the wrong place, they can become a serious health concern.
Understanding the signs, causes, and risk factors of blood clots can help you recognize when to seek medical attention and take steps to protect your health.
What Is a Blood Clot?
A blood clot is a gel-like clump of blood that forms to stop bleeding when you’re injured. This is a normal and necessary function. However, problems can arise when clots form inside veins or arteries without an injury, or when they don’t dissolve properly.
These clots can restrict blood flow or travel to other parts of the body, leading to potentially life-threatening complications.
Common Types of Blood Clots
Blood clots can occur in different parts of the body, and each type comes with its own risks:
- Deep Vein Thrombosis (DVT): A clot that forms in a deep vein, usually in the legs
- Pulmonary Embolism (PE): Occurs when a clot travels to the lungs and blocks blood flow
- Arterial Clots: Form in arteries and can lead to heart attacks or strokes
- Superficial Clots: Occur closer to the skin and are generally less dangerous but still require attention
Signs and Symptoms
Symptoms can vary depending on where the clot forms. In some cases, there may be no warning signs.
Symptoms of DVT (commonly in the leg):
- Swelling in one leg
- Pain or tenderness
- Warmth in the affected area
- Red or discolored skin
Symptoms of a pulmonary embolism (medical emergency):
- Sudden shortness of breath
- Chest pain, especially when breathing deeply
- Rapid heart rate
- Coughing, sometimes with blood
Symptoms of arterial clots:
- Severe pain
- Coldness or numbness in a limb
- Sudden weakness or difficulty speaking (possible stroke)
If you experience symptoms of a pulmonary embolism or stroke, seek emergency medical care immediately.
What Causes Blood Clots?
Blood clots can develop when blood flow slows down, blood vessels are damaged, or the blood becomes more prone to clotting.
Common causes and contributing factors include:
- Long periods of inactivity (such as sitting during travel or bed rest)
- Surgery or injury
- Smoking
- Obesity
- Pregnancy and the postpartum period
- Certain medications, including hormonal birth control or hormone therapy
Who Is More at Risk?
“Some individuals are more susceptible to developing blood clots due to underlying health conditions or lifestyle factors,” shares Jeremey Chuang MD, a PIH Health Hematology/Oncology and Internal Medicine physician.
You may be at higher risk if you:
- Have a personal or family history of blood clots
- Are over the age of 60
- Have cancer or are undergoing cancer treatment
- Live with chronic inflammatory conditions, such as inflammatory bowel diseases like ulcerative colitis or Crohn’s disease
- Have heart disease or lung disease
- Have a clotting disorder
- Are pregnant or have recently given birth
- Sit or lie down for extended periods (such as during long flights or recovery from illness)
Inflammatory conditions can increase the body’s tendency to form clots, which is why individuals with certain chronic illnesses may face a higher risk.
Prevention and When to Seek Care
While not all blood clots can be prevented, there are steps you can take to reduce your risk:
- Stay active and avoid long periods of sitting
- Stay hydrated
- Follow your doctor’s recommendations after surgery or during illness
- Know your personal risk factors
According to Dr. Chuang, “Blood clots can happen to anyone, but understanding your risk can make a meaningful difference. Increased awareness helps individuals recognize symptoms early and seek care before complications arise.” Seek medical attention right away if you notice symptoms of a blood clot, especially sudden shortness of breath, chest pain, or swelling in one leg. Early detection can be lifesaving. To learn more about your risk and prevention, speak with your doctor or find a provider at PIHHealth.org/Doctor.
