I’m guessing you have heard about blood clots. But have you heard of the term deep vein thrombosis, or seen the acronym DVT? Do you know what a deep vein thrombosis is and how you could get one? And are you aware that a DVT can lead to a life-threatening pulmonary embolism? Read on to learn more including how to reduce your risk of dangerous deep vein thrombosis.
How does blood clot?
Blood clotting is a normal process to prevent bleeding. When a blood vessel is injured, the damaged cells in the vessel wall send out chemical signals that slow or stop bleeding. Importantly, your body makes blood clots to stop bleeding and then breaks them down. However, in certain circumstances, your body may be unable to break down a clot, which can cause a serious health problem.
- The blood vessel narrows. Firstly, chemical signals cause the injured vessels to narrow to prevent more blood from leaking out.
- Platelets travel to the site of the injury. The chemical signals travel through your blood to the spleen which releases platelets into your blood. The vessel walls at the injury site become sticky and capture platelets as they float past.
- A platelet plug forms. The platelets change shape and become stickier, allowing them to attach to the vessel wall and clump together into a plug.
- The blood clot forms. When there is a blood vessel injury, platelets release molecules into the blood that help turn on clotting factors that are normally turned off. Fibrin, a long, thin, sticky protein is an important clotting factor. When turned on, fibrin forms a mesh to hold the platelet plug in place and traps red blood cells that form a blood clot. The platelets contract to pull the two sides of the damaged vessel closer together, so it is easier to repair.
Once the blood clot is formed, your body’srepairs the injury. In ideal scenarios, the factors in your blood start to break down the blood clot. But sometimes your body cannot break up the clots.
What is deep vein thrombosis (DVT)?
Deep vein thrombosis (DVT) is a blood clot in a deep vein – a vein located near the bone and surrounded by muscle – usually in the lower leg, thigh or pelvis. (This type of blood clot does not cause heart attack or stroke. In contrast, a blood clot in an artery, usually in the heart or brain, can cause a heart attack or stroke.)
A DVT can occur if:
- The flow of blood slows down in your body’s deep veins.
- Something damages the blood vessel lining.
- The makeup of the blood itself changes so that blood clots form more easily.
What are the symptoms of a deep vein thrombosis?
It is important to know the symptoms of a DVT in the leg which are:
- Throbbing pain or cramping in 1 leg – but rarely in both legs. The pain is usually in the calf or thigh, when walking or standing up.
- Swelling in 1 leg – but rarely both legs.
- Warm skin around the painful area.
- Red or discolored/darkened skin around the painful area, which unfortunately can be harder to see if you have dark skin.
- Swollen veins that are hard or sore when you touch them.
Importantly, these symptoms can also appear in your arm or other areas where a blood clot can develop.
How do doctors diagnose a DVT?
If your doctor suspects a deep vein thrombosis, he/she will evaluate your symptoms, take a medical history, and perform a physical exam. Additionally, your doctor may order imaging or blood tests, which could include a:
- D-dimer blood test which measures a substance in the blood that is released when the proteins that help stop bleeding in a blood clot dissolve. If the test shows high levels of the substance, you may have DVT. Your doctor may order this test if you are otherwise healthy with no risk factors for DVT.
- Compression ultrasound which looks for blood clots in the deep veins of your legs by examining the flow of blood through your veins. During the ultrasound, the technician may press on your veins to see if they compress normally or are stiff with blood clots.
- Magnetic resonance venography which takes images of your veins after you are given a special dye through an IV. Generally, doctors only use this test if they cannot diagnose a DVT from the compression ultrasound results.
Do you have an increased risk of developing a DVT?
Unfortunately, quite a few factors increase your chances of getting a DVT.
For example, you have a higher risk if you:
- Are over 60 years of age.
- Are overweight.
- Have had previous occurrences of DVT.
- Take the contraceptive pill or hormone replacement therapy (HRT).
- Have varicose veins.
Additionally, your risk of DVT increases if you don’t move for long periods of time, which can occur:
- During a long trip by plane, car, or train.
- When on bed rest – at home, in a hospital, or nursing home.
- After surgery. Importantly, the chance of developing a blood clot is highest in the first 3 months after surgery.
Furthermore, you may have inherited genes that increase your likelihood of developing blood clots. And certain medical conditions, such as blood clotting disorders, lupus, heart problems, cancer, and other serious illnesses (including COVID-19) increase the likelihood of DVT. Similarly, physical trauma from a broken bone, muscle injury, or other serious injury can also increase your risk.
Additionally, your risk of DVT increases if you are:
- In the hospital or recently discharged – especially if your condition limits your mobility, such as after surgery.
- Pregnant or have had a baby in the previous 6 weeks.
Finally, it’s important to know that sometimes DVT occurs for no obvious reason – so don’t rule out the possibility just because none of the above factors apply to you.
DVT can lead to dangerous pulmonary embolisms.
Part of a blood clot that formed in a deep vein in one area of the body, can break off and travel in the blood to another area of the body. This is called an embolus. As it travels, an embolus can lodge itself in a blood vessel which can block the blood supply to a particular organ. This blockage of a blood vessel by an embolus is called an embolism.
When a DVT breaks off from your leg (or other area) and travels to your lungs, you can have a life-threatening blockage of your lung’s blood vessels, which is called a pulmonary embolism.
Note that although DVT is the most common cause of pulmonary embolism, other causes include air bubbles in your circulatory system, a DVT in your upper body, and fat embolus (often linked to a large bone breaking).
Why are pulmonary embolisms so dangerous?
Without treatment, pulmonary embolisms restrict blood flow in your lungs, which can cause serious complications and even death. Complications include:
- Cardiac arrest – when your heart suddenly stops beating.
- Cardiac arrhythmia – an irregular heart rhythm.
- Pleural effusion – a buildup of fluid in the membrane (pleura) around your lungs.
- Pulmonary hypertension – high blood pressure in your lungs.
- Pulmonary infarction – death of lung tissue.
Pulmonary embolism symptoms.
It’s possible to have a pulmonary embolism that doesn’t cause symptoms. However, as the clot blocks more and more blood flow, the following symptoms may develop:
- Coughing, including a cough that produces bloody mucus.
- Heart palpitations – sensations of your heart racing or pounding.
- Pain or swelling in your leg.
- Sharp and sudden chest pain.
- Shortness of breath that worsens with exertion.
What are the risk factors for pulmonary embolisms?
Risk factors for pulmonary embolisms include:
- Genetic predisposition to blood clots.
- Family history of blood clotting disorders.
- Surgery or injury (especially to the legs) or orthopedic surgery.
- Limited mobility, such as extended bed rest, traveling long distances, or paralysis.
- Previous history of blood clots.
- Older age.
- Cancer and cancer treatments.
- Certain medical conditions, such as heart failure, chronic obstructive pulmonary disease (COPD), high blood pressure, stroke, and inflammatory bowel disease.
- Certain medications, including birth control pills and estrogen replacement therapy.
- During and after pregnancy.
- Varicose veins.
- Cigarette smoking.
Additionally, a pulmonary embolism is more likely to develop after severe injuries, burns or fractures.
How do doctors diagnose a pulmonary embolism?
If your doctor suspects a pulmonary embolism, he/she will perform a physical exam, ask about your symptoms, and order one or more tests which could include:
- Blood tests to check if you have an increased risk of blood clotting.
- Chest X-rays to examine your heart and lungs.
- CT pulmonary angiography which uses X-rays and specialized computers to create cross-sectional, 3D images of your lungs and pulmonary arteries.
- Doppler ultrasound to estimate the blood flow through your blood vessels that help identify DVT in your legs.
- Echocardiogram to view your heart’s structures and blood vessels.
- Lab tests, which may include measuring your blood oxygen levels or measuring the balance of oxygen and carbon dioxide.
- Pulmonary angiogram which uses a small catheter (a hollow tube) and a contrast dye to see how blood flows through the pulmonary arteries.
- Ventilation-perfusion (V/Q) scan which tracks blood flow after injecting a tracer into your veins to check for pulmonary hypertension.
DVT and pulmonary embolisms in hospital patients.
Unfortunately, many hospital patients develop DVT and subsequent pulmonary embolisms. In fact, according to the CDC (Centers for Disease Control and Prevention) hospitalization is a major risk factor for blood clots. Consider these sobering facts:
- About 50% of blood clots occur during or within 3 months of a hospital stay or surgery.
- Many of these blood clots could be prevented.
- Nearly 50% of all hospital patients do not receive proper prevention measures.
- Approximately 10% of hospital deaths are related to pulmonary embolisms.
How do doctors treat DVT or pulmonary embolism?
Rapid treatment for DVT or pulmonary embolism is critical for good outcomes. Once a doctor diagnoses DVT or pulmonary embolism, the treatments can include:
- For either condition, your doctor may prescribe blood-thinning medicines, such as warfarin or rivaroxaban, which keep blood clots from getting larger and stop new clots from forming. You may get your medication via a shot, a pill or an IV. Importantly, you may need to take these medications for many months, or indefinitely.
- If you have a large blood clot that causes severe symptoms or other serious complications. your doctor may prescribe IV medication to dissolve blood clots (called thrombolytics). However, thrombolytics can cause sudden bleeding, so doctors only use them for serious and potentially life-threatening cases, such as pulmonary embolisms.
- If you cannot take blood thinners, your doctor may insert a filter into the vena cava (the main vein that carries blood from your legs to your heart). This filter catches blood clots before they travel to the lungs, which prevents pulmonary embolisms. However, the filter doesn’t stop the formation of new clots.
- In some cases, including emergencies, a doctor may remove or destroy the clot. During the procedure, a doctor uses tiny tools to remove a large blood clot or to deliver clot-busting medication directly to a clot in your leg or lung.
What to do if you think you might have a DVT or pulmonary embolism?
Get medical help as soon as possible if you think you have DVT or pulmonary embolism. Time is not your friend.
Follow these guidelines from the CDC:
Importantly, be persistent if you suspect DVT or pulmonary embolism, even if your doctor doesn’t take your concerns seriously.
There is no time to waste if you have a DVT or pulmonary embolism! Alarmingly, about 1/3 of patients with undiagnosed/untreated pulmonary embolisms don’t survive.
A lesson in persistence from Serena Williams.
Serena shares her story to help others. Shortly after giving birth, Serena developed shortness of breath. Because she had a history of pulmonary embolisms caused, she told her nurse she needed an immediate CT scan with contrast and a blood thinner.
The nurse thought Serena was confused, but Serena insisted. A doctor performed an ultrasound on her legs, but Serena insisted she needed a CT scan and an IV drip of blood thinner.
After a normal ultrasound, a CT scan found several small blood clots in her lungs. They immediately started her on an IV blood thinner, which likely saved her life.
How can you reduce your risk of getting a deep vein thrombosis?
Fortunately, there are steps you can take to lower your risk of getting a deep vein thrombosis, including the following:
- Maintain a healthy weight.
- Stay active – even regular walks can make a difference.
- Drink plenty of fluids to avoid dehydration.
- Don’t sit still for extended periods – try to get up and move every hour or so.
- Avoid crossing your legs while seated.
- Do not smoke.
- Minimize the amount of alcohol you drink.
Additionally, when traveling more than 3 hours by plane, train or car, reduce your risk of deep vein thrombosis by:
- Wearing loose clothing.
- Drinking plenty of water.
- Avoiding alcohol.
- Walking around when possible.
Are you going to the hospital or having surgery?
Firstly, ask your doctor if your condition or procedure increases your risk of DVT. If you have an elevated risk, make sure every doctor on your team understands your risk.
Additionally, even without an elevated risk, ask your doctor what preventive measures will be taken to reduce your chances of developing a DVT, particularly if you will undergo major surgery.
- Asking your doctors what steps you should take to reduce your risk. And then following their recommendations.
- Staying as active as possible and walking around if you can. (But don’t walk alone without clearance from your doctor.)
- Performing simple exercises such as moving your toes up and down and rotating your ankles in circles. And ask your medical team for suggested exercises.
Prior DVT? Learn how to reduce your risk of recurrence of a deep vein thrombosis.
As you recover from DVT, ask your doctor how to reduce your risk of developing another deep vein thrombosis, considering these factors:
- Understand possible complications. A condition called post-thrombotic syndrome can develop following DVT. If you experience pain, itchiness, or swelling, tell your doctor.
- Prevent a repeat DVT. To lower your chances of a recurrence, ask your doctor about how to reduce your risk, get regular checkups, and take all medicines as prescribed.
- Make healthy lifestyle changes. Ask your doctor what lifestyle changes you need to make. Your doctor may recommend dietary changes, weight loss, exercise, and if applicable, quitting smoking.
- Take care of your mental health. After DVT, many people feel anxious, fearful, and stressed. Consider getting professional help if you need support.
Read these blog posts for tips that can help you get the best care possible:
- Why are Second Opinions Important?
- 10 Steps to Reduce Your Risk of Diagnostic Error
- Personal Stories of Diagnostic Errors.
- How Can You Get the Best Healthcare? Actively Participate!
- Understanding Medical Information Is Harder Than Most Realize.