Table of Contents
- Blood clot definition and facts
- What are blood clots?
- What causes blood clots (blood clots in veins or arteries)?
- What causes blood clots (blood clots in the heart and medical problems)?
- What are the signs and symptoms of blood clots?
- What are the risk factors for forming blood clots?
- What happens when a blood clot forms in the leg travels to the lung?
- What happens when blood clots form and travel to the heart?
- How are blood clots found or diagnosed?
- What tests are used to diagnose blood clots?
- What is the treatment for blood clots?
- What kind of doctors treat blood clots?
- What are the complications of blood clots?
- How can blood clots be prevented?
Quick GuideDVT in Pictures: Symptoms of Deep Vein Thrombosis, Beyond Leg Pain and More
How are blood clots found or diagnosed?
The first step in making the diagnosis of a blood clot is talking to the patient and family to understand the situation. The blood clot itself does not cause a problem. It's the location of the blood clot and its effect on blood flow that causes symptoms and signs. If a blood clot or thrombus is a consideration, the history may expand to explore risk factors or situations that might put the patient at risk for forming a clot.
Venous blood clots often develop slowly with a gradual onset of swelling, pain, and discoloration. Symptoms of a venous thrombus will often progress over hours.
Arterial thrombi occur as an acute event. Tissues need oxygen immediately, and the loss of blood supply creates a situation in which symptoms begin immediately.
There may be symptoms that precede the acute artery blockage that may be warning signs of the potential future complete occlusion of the blood vessel.
- Patients with an acute heart attack may experience angina or chest discomfort (pressure, pain, indigestion, fatigue) in the days and weeks prior to the heart attack. It is important to remember that women may experience atypical and non-specific symptoms as part of their angina equivalent, including fatigue and malaise.
- Patients with peripheral artery disease may have pain with walking (claudication)
- A TIA (transient ischemia attack, mini-stroke) in which the symptoms resolve without treatment may precede a stroke.
Physical examination can assist in providing additional information that may increase the suspicion for a blood clot.
- Vital signs may be helpful in deciding how stable the patient is doing. These include blood pressure, pulse rate, respiratory rate, body temperature and oxygen saturation (what percentage of red blood cells have oxygen attached).
- Heart monitoring and an EKG may be ordered to assess heart rate and rhythm.
- Venous thrombi may cause swelling of an extremity (arms, legs). The limb may appear to be red, warm, and tender; sometimes the appearance is difficult to distinguish from cellulitis or an infection of the extremity. If there is concern about a pulmonary embolus, the doctor may examine the lungs to listen for abnormal sounds caused by an area of inflamed lung tissue.
- Arterial thrombus symptoms are much more dramatic. If a leg or arm is involved, the tissue may be white because of the lack of blood supply. Also, it may be cool to touch and there may be loss of sensation and movement (paralysis). The patient may be writhing in pain.
Arterial thrombus is also the cause of heart attack and stroke (cerebrovascular accident) and their associated symptoms.
Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. Chest. 2012;141(2_suppl)
Dzsheka MS, et al. Stroke and bleeding risk in atrial fibrillation. Clin Cardiol.2014, Oct, 37(10)
Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.
Kearon, C., et al. "Antithrombotic Therapy for VTE Disease: Chest Guideline and Expert Panel Report." Chest. 2016;149(2):315-352. IMAGES:
1.Universal Images Group / Getty Images
8.Brand X Pictures / Getty Images