Blood clots are a serious public health concern. To prevent complications, it is important to know the symptoms of blood clots and be able to identify them as quickly as possible.
When the blood clots, it turns from a liquid into a gel that stops it from flowing. This is important for preventing blood loss when someone gets a cut or scrape.
Clotting is a vital mechanism to prevent the body from harm. Without blood clotting, cuts would keep bleeding, and small leaks in the internal blood vessels could cause serious problems.
Blood clots are a serious public health concern. According to the Centers for Disease Control and Prevention (CDC), as many as 100,000 people die from blood clots each year in the United States.
This article looks at types of blood clot, their symptoms, and some treatment options.
Blood clots can result in a range of different medical conditions depending on where they travel in the body.
Blood clots occurring in a vein can lead to DVT or pulmonary embolism. DVT is characterized by a blood clot in a deep vein — usually in the leg, pelvis, or arm. In pulmonary embolism, a blood clot has traveled from a deep vein into a lung.
A blood clot in the lung can also occur in people without a DVT, and not all people with DVT will develop an embolism.
When blood clots form directly in the arteries, two major medical events can occur: heart attack (wherein a blood clot prevents blood from flowing to the heart) and ischemic stroke (wherein a blood clot prevents blood from flowing to part of the brain).
It is important to note that DVT does not cause heart attack or stroke. Blood clots in the veins and arteries have different effects on the body and different complications.
Many blood clots occur after surgery. In fact, the CDC say that 50% of all internal venous blood clots develop “during or soon after a hospital stay or surgery.”
The symptoms of a blood clot depend on the location and severity of the clot. It is important to know the symptoms and be able to identify them quickly. Early diagnosis and treatment can help prevent complications and death from blood clots.
The symptoms of a blood clot vary depending on their location.
Arm or leg
The most common place for a venous blood clot to develop is the leg, most often in the calf, and the symptoms are similar in the arm.
Around 50% of people with DVT have no symptoms at all. If they do occur, symptoms of a blood clot in the leg or arm can include:
- a warm sensation
The pain can feel similar to a pulled muscle or heavy ache. Whether or not the symptoms indicate DVT, they are issues that need the attention of a doctor as soon as possible.
To diagnose DVT, a doctor will perform certain tests, such as blood tests and ultrasound scans.
They may look for more detailed signs of DVT, including the location and amount of swelling (and how this compares with the other limb) and how the sensations of tenderness relate to the form of the veins in the leg.
Doctors commonly use medications to prevent and treat DVT.
For a blood clot in the leg, wearing compression stockings for up to 2 years after the event can help with swelling and pain.
In severe cases, a doctor may need to remove the clot surgically.
A blood clot in the lung is known as a pulmonary embolism.
Some research suggests that in the U.S., over 200,000 people develop venous thrombosis each year. Around 50,000 of these cases are complicated by pulmonary embolism.
The symptoms of a blood clot in the lung can include:
- difficulty breathing
- a fast heartbeat or an irregular heartbeat
- chest pain or discomfort that usually gets worse with a deep breath or coughing
- coughing up blood
- very low blood pressure
- lightheadedness or fainting
Other serious symptoms can include:
- anxiety or a sense of dread
Pulmonary embolism requires emergency medical attention.
Doctors can treat this condition using medications that dissolve blood clots, or thrombolytics. They may also prescribe medicines that prevent blood clotting, called anticoagulants.
If the clot is small, people can recover from pulmonary embolism with effective treatment. However, it can leave some lasting lung damage.
Large clots can prevent blood from reaching the lungs, which can be fatal.
Blood clots in the abdomen can cause the following symptoms:
- severe pain in the abdomen
- bloody stool
It can be difficult to diagnose a blood clot in the abdomen or pelvis. Doctors may use a CT scan or other imaging studies to look for blood clots in this area and to rule out other causes of these symptoms.
A blood clot in an artery around the heart can lead to a heart attack.
The symptoms of a heart attack include:
- chest discomfort — such as pressure, fullness, or pain — that occurs in the center of the chest and lasts for more than a few minutes
- pain or discomfort in other body parts, such as one or both arms, the back, jaw, stomach, or neck
- shortness of breath, with or without chest discomfort
- other signs, such as a cold sweat, nausea, or lightheadedness
The symptoms can differ between males and females. Chest pain is the most common symptom overall, but females are more likely to experience shortness of breath, nausea or vomiting, and back or jaw pain.
A heart attack is a medical emergency. People should seek emergency treatment if they notice any symptoms.
A blood clot in the brain can lead to ischemic stroke. This occurs when a blood clot blocks an artery, preventing blood from flowing to certain areas of the brain.
Symptoms of ischemic stroke include a sudden onset of:
- numbness or weakness in the face, arm, or leg, especially on one side of the body
- difficulty speaking or understanding speech
- vision problems in one or both eyes
- difficulty walking
- dizziness or loss of coordination
- a severe headache with no known cause
A stroke is a medical emergency. People should seek emergency treatment if they notice any symptoms.
The following tips can help prevent blood clots:
- Move around as soon as possible after being confined to a bed, such as after surgery, illness, or injury.
- When sitting for long periods, get up and walk around every 2–3 hours.
- Exercise the legs while sitting, such as tightening and relaxing the leg muscles and performing heel and toe raises.
- Maintain a moderate weight and avoid a sedentary lifestyle.
- Talk to a doctor about using compression stockings or anticoagulants to prevent clots.
The National Blood Clot Alliance have produced a “passport to safety” for preventing DVT while traveling. They suggest practical prevention measures, such as staying hydrated, moving the lower legs, and getting up for a walk.
Some people are more likely to develop blood clots than others. Risk factors for blood clots include:
- recent surgery
- recent hospitalization
- a family history of blood clots
- slow blood flow due to limited movement, confinement to a bed, or sitting still for a long time
- increased estrogen from birth control pills, menopause medications, or pregnancy
- damage to the vein linings due to fractures, muscle trauma, or long-term vascular conditions, such as diabetes
Some medical conditions can also increase the risk of DVT, including:
- heart disease
- lung disease
- cancer and some cancer treatments
- inflammatory bowel disease
- inherited clotting disorders
The risk of a blood clot increases when the person has more risk factors.
Blood clots are a major public health concern.
Knowing the symptoms of a blood clot in different areas of the body can help people identify blood clots early and prevent long-term complications.