Signs of DVT in the leg
What are the symptoms – and what can be done?
Everyone has probably heard of the term thrombosis, but what exactly is it?
Thrombosis occurs when a blood clot – known as a "thrombus" – forms in a blood vessel in the body and completely or partially blocks it. There are several forms, but usually a so-called "deep vein thrombosis" (DVT) or deep veins of the leg is meant when we speak of thrombosis. It occurs when a blood clot forms in one of the deep veins, usually starting in the lower leg, and obstructs or stops the flow of blood back to the heart.
That sounds dramatic, but it only becomes really dangerous when the thrombus breaks loose and is transported to the lungs by the blood. There it can clog blood vessels in the lungs and cause a life-threatening pulmonary embolism. After signs of DVT in the leg, permanent impairment of the deep vein system may result, and thus so-called post-thrombotic syndrome (PTS). In the long term, this can lead to swelling, pain, a feeling of heaviness and skin changes. However, even if the disease progresses mildly, the risk of a recurrence of deep vein thrombosis is increased. It is clear that leg vein thrombosis is not something to be taken lightly.
Symptoms of deep vein thrombosis
How can we recognize such signs of DVT in the leg if it should occur? In many cases the affliction is not noticed by those affected.
If symptoms occur, signs of DVT in the leg are often noticeable by relatively diffuse symptoms such as leg pain, often only when stepping or tensing the calf muscles, or an unusual numbness in the legs. Typical signs include newly appearing swelling, pressure pain, a feeling of tension or warmth, vein pain, and visible veins on the leg. These symptoms usually occur suddenly and only in one leg. If DVT is suspected, the doctor can determine if thrombosis is present by carrying out an ultrasound examination. This is important, as timely diagnosis and appropriate treatment significantly reduce the risk of serious complications.
Who is at risk?
Year after year, signs of DVT in the leg occur in one in 1,000 people. The risk increases with age and men are affected slightly more often than women. Further risk factors include obesity, smoking and prolonged periods of restricted movement, for example with prolonged hospitalization – or sitting for long periods, e.g. on an airplane. The risk also increases in the case of heart failure, infections, damage to vessel walls, blood clotting disorders or slower blood flow rates, for example with venous congestion. The more risk factors present, the higher is the risk of DVT in the leg.
Television as a risk factor?
Not just those going on a trip or already having a vein condition are at a higher risk of thrombosis. Sitting at a desk for long periods or in front of the TV are also associated with higher risk. In a systematic review and meta-analysis of three research studies, researchers from the University of Bristol in the United Kingdom found in 2022 that the risk of thrombosis was higher the longer the study subjects sat in front of the television. Those who spent more than four hours a day watching television had a more than one-third increased risk of thrombosis than people who watched less than 2.5 hours a day.
Preventing thrombosis – how?
What can be done to reduce your own risk of DVT in the leg? Risk factors such as age, gender or hospitalization can hardly be influenced. What can be influenced however is the speed of venous flow, specifically through exercise for example and by wearing compression stockings.
Regular exercise in the form of walking, running, cycling and other sports is good for the cardiovascular system and promotes the speed of venous flow. It is also important to stand up regularly when sitting for long periods of time and to activate the so-called "calf muscle pump". If the calf muscles are activated by movement, this intermittently compresses the veins, helping to "pump" the blood back towards the heart. If standing up is not possible, this can also be achieved by simple exercises that move the ankle, e.g. foot rocking or circling with the feet.
Your doctor may have advised you to wear compression stockings before a flight to prevent leg vein thrombosis. Wearing compression stockings also makes sense in other situations. By applying controlled pressure, they improve the speed of venous flow by specifically reducing the diameter of the leg veins to support the return of blood to the heart. This leads to less congestion and decreases the risk of thrombus formation.
The best protection
Deep vein thrombosis is an acute venous disease. If you notice associated symptoms, you should immediately seek medical treatment. Fortunately, there are some measures you can take to significantly reduce your risk of DVT. In short, avoid sitting for long periods of time, maintain a healthy body weight, make sure you get plenty of exercise, and be sure to wear support stockings or compression stockings if needed – for the sake of your health.