
By Rick Schultz
A DVT (deep vein thrombosis) is a condition in which blood clots form in veins located deep inside the body, usually in the thigh or lower legs. This usually causes pain and swelling in and around the affected area. If the DVT appears above the hip, then it is considered a more serious problem that needs to be addressed immediately with a medical provider.
General:
- Common – more than 200,000 cases per year in the US
- Detectable – usually the affected area is swollen, feels warm, tender and/or painful to touch. Symptoms usually worsen over time.
- Treatable – usually by blood thinners
- Diagnosis – usually by lab tests and ultrasound imaging (can use contrast)
- Can last – several months to lifetime
- Family history – may increase likelihood
- Dangerous – if a blood clot breaks off and travels to the lungs, this can potentially cause a blockage or pulmonary embolism.
Risk Factors (according to Mayo Clinic):
- Age. Being older than 60 increases your risk of DVT, though it can occur at any age.
- Sitting for long periods of time, such as when driving or flying. When your legs remain still for hours, your calf muscles don’t contract, blood pools in lower legs. Muscle contractions normally help blood circulate.
- Prolonged bed rest, such as during a long hospital stay, or paralysis. Blood clots can form in the calves of your legs if your calf muscles don’t move for long periods.
- Injury or surgery. Injury to your veins or surgery can increase the risk of blood clots.
- Pregnancy. Pregnancy increases the pressure in the veins in your pelvis and legs. Women with an inherited clotting disorder are especially at risk. The risk of blood clots from pregnancy can continue for up to six weeks after you have your baby.
- Birth control pills (oral contraceptives) or hormone replacement therapy. Both can increase your blood’s ability to clot.
- Being overweight or obese. Being overweight increases the pressure in the veins in your pelvis and legs.
- Smoking. Smoking affects blood clotting and circulation, which can increase your risk of DVT.
- Cancer. Some forms of cancer increase substances in your blood that cause your blood to clot. Some forms of cancer treatment also increase the risk of blood clots.
- Heart failure. This increases your risk of DVT and pulmonary embolism. Because people with heart failure have limited heart and lung function, the symptoms caused by even a small pulmonary embolism are more noticeable.
- Inflammatory bowel disease. Bowel diseases, such as Crohn’s disease or ulcerative colitis, increase the risk of DVT.
- A personal or family history of DVT or PE. If you or someone in your family has had one or both, you might be at greater risk of developing DVT.
- Genetics. Some people inherit genetic risk factors or disorders, such as factor V Leiden, that make their blood clot more easily. An inherited disorder on its own might not cause blood clots unless combined with one or more other risk factors.
- No known risk factor. Sometimes, a blood clot in a vein can occur with no apparent underlying risk factor. This is called an unprovoked VTE.
Some Prevention Measures:
- Avoid sitting still
- If you had a surgery, get up and move (walk) as soon as you can
- If sitting for a while, don’t cross your legs which can block blood flow
- If travelling a long distance by car, stop every hour and walk around
- If travelling on a plane, stand/walk occasionally. If you can, do calf raises and shin raises (raise and lower heels while keeping toes on the floor then raise and lower toes while keeping heels on the floor)
- Don’t Smoke – Smoking increases your risk of getting DVT
- Regular Exercise – lowers your risk of blood clots.
- Manage your weight –Obesity is a risk factor for DVT.
- Wear compression socks (closed toe to under knee) when exercising – 20-30 mmHg
- Wear compression socks (closed toe to under knee) when traveling – 15-20 mmHg
So, Why This Article?
The body forms blood clots all the time, and the body also usually absorbs these clots right away. It’s those that the body doesn’t absorb that can be life-threatening.
Lately, I am seeing more people with DVT. As can be seen below, DVT affect both athletes and sedentary people.
I have a friend who is an endurance athlete, an Ironman triathlete to be exact that developed a large DVT in his right leg. My stepsister, (77 years old and sedentary) is currently in the hospital on blood thinning medicine with a DVT in her leg and her lung. What alerted both was a severe pain in the lower leg.
Where did this come from?
My guess for the triathlete was from an overuse injury where he injured his calf muscle and sat around for a few days. Blood pooled and DVT. For my stepsister, she mostly sits in a chair with feet flat on the floor. Blood pools in the lower leg and DVT.
Moral of the story, DVTs seem to be more common than we think they are, and it doesn’t matter if you are a runner, cyclist or sedentary. If you are experiencing pain or swelling in your lower leg(s), make sure to see your doctor ASAP and ask for their opinion on if you have a DVT – it might just save your life!
References:
- Deep vein thrombosis – Symptoms and causes – Mayo Clinic
- What is Venous Thromboembolism? | CDC
- Deep vein thrombosis – Wikipedia
Coach Rick Schultz is an avid cyclist who trains, races and coaches in Southern California. Rick is an engineer by trade, and in addition to being a coach, he’s a bike fitter and prolific product reviewer. He’s the author of Stretching & Core Strengthening for the Cyclist in the RBR eBookstore. Check his product reviews website, www.biketestreviews.com, and his coaching site, www.bikefitnesscoaching.com. Click to read Rick’s full bio.
Hey Coach.
Good article.
Note: *Extreme* endurance exercise, can stimulate both pro, as well as anti-coagulation factors and processes, in many individuals.
Example – Check out the 2002 article by Smith: “Effects of strenuous exercise on hemostasis”
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1751362/pdf/v037p00433.pdf
I agree with DURING EXERCISE, but, from other articles, it’s what happens after exercise that tends to be the culprit.
As a Factor V Leiden genetic individual, it was not until I had a DVT at the age of 45 and then subsequent multiple pulmonary emboli (both lung splattered with clots) did I know I was always at risk. I am a life long athlete and now have a lifetime subscription to blood thinners. Fortunately, I am well despite it all. Warning signs for the pulmonary emboli was a slow diminishing in lung capacity. I just thought the lack of being able to stay up with the hammerheads was just a dip in the cyclic nature of training. Then came the day that a stitch in my side like a normal cramp persisted for over 30 minutes and the only breathing I could allow without a sharp stabbing pain was extremely shallow. A week in the hospital to regain control and I was back up and running. I am very thankful for the reprieve.
Intense physical activity (marathon level) followed by prolonged sitting (4 hour plus car ride, plane flight) is the deadly scenario. If you are worried, a single aspirin pre flight/drive offers the best protection (along with walking the aisle once an hour or take a 3 minute break if driving), As a physician who has been there, and taken his 6 months of pradaxa, I speak from personal experience. Routine training rides are not the risk.