A clot forming in a deep vein of the leg blocks the outflow, making the limb swell and ache. The immediate danger is that part of it breaks off and lodges in the lungs, which is why suspected DVT is assessed the same day.
Deep vein thrombosis is a blood clot in one of the deep veins, usually of the calf or thigh. It causes swelling, pain and warmth in the limb, and it can break off and travel to the lungs. Diagnosis is by duplex ultrasound and a blood test, and treatment is anticoagulation, usually for at least three months. Surgery is rarely needed but compression and early walking matter throughout.
Blood clots in a vein when three things combine: flow slows, the vein wall is injured, and the blood is more prone to clotting than usual. Long immobility, recent surgery, trauma, cancer, pregnancy, the contraceptive pill and inherited clotting tendencies all push one or more of those factors in the wrong direction.
The clot itself blocks the vein, so blood cannot leave the limb easily. The leg swells, aches and feels tight, and the calf is often tender. That is uncomfortable but not in itself dangerous.
What is dangerous is embolism. A fragment can break off, travel through the heart and lodge in the lungs, causing sudden breathlessness, chest pain and in severe cases collapse. That risk is highest in the first days and is the reason anticoagulation is started promptly rather than after the weekend.
There is also a long term cost. A vein that has been clotted often never regains normal valve function, and the leg is left with chronic swelling, skin changes and sometimes ulceration. That condition, post-thrombotic syndrome, is prevented far more easily than it is treated, mostly by early walking and proper compression.
Any unexplained unilateral leg swelling should be assessed rather than watched, because the consequence of missing it is serious and the test is quick.
History and examination establish how likely a clot is, using a standard scoring system.
A D-dimer test helps rule out clot in lower risk patients. It is not useful as a rule-in test on its own.
The definitive test. The veins are compressed with the probe; a vein that will not compress contains clot.
Treatment is started as soon as the diagnosis is made, or sooner if suspicion is high and scanning will be delayed.
Graduated compression is fitted and you are encouraged to walk, not to rest in bed.
Where no obvious trigger exists, further investigation may be arranged, since an unprovoked clot occasionally points to another condition.
Pain and swelling begin to ease. Anticoagulation is established. Walk regularly and elevate the leg when resting.
Swelling continues to settle. Compression is worn daily. Normal activity resumes; avoid contact sports while anticoagulated.
The duration of anticoagulation is reviewed based on whether the clot was provoked and on bleeding risk.
Late swelling and skin changes, if they are going to appear, do so over this period. Continued compression reduces the risk.
Anticoagulation stops the clot extending and greatly reduces the chance of it travelling to the lungs, and that is its main purpose. It does not dissolve the existing clot quickly; the body does that over weeks to months. Many patients are left with some permanent damage to the vein valves, and around a third develop some degree of long term swelling. Early walking and consistent compression measurably reduce that risk, which is why they are emphasised so strongly.
Anticoagulation trades clotting risk for bleeding risk, and that balance is set individually.
What you do over the following months determines how the leg is in five years.
The opposite. Early walking is safe, does not increase the risk of embolism, and reduces long term swelling. Bed rest makes the leg and the clot worse.
Anticoagulants stop the clot growing and let the body break it down over weeks to months. They are not clot busters, which are reserved for rare severe cases.
Compression reduces the chance of chronic swelling and ulceration over the following years, so it is often continued well beyond the point the leg feels normal.
Having had one clot is itself a risk factor for another, particularly if there was no obvious trigger. That is why the duration of treatment is reviewed rather than fixed at three months for everyone.
DVT is often first noticed after surgery or trauma, and the long term consequence, a swollen leg with skin damage, is exactly what this unit treats. Managing the clot and its aftermath under one team means the leg is followed rather than discharged.
Investigation and treatment of DVT are commonly covered by health insurance and government schemes. Most patients are treated as outpatients with tablets or injections, so cost is usually modest compared with surgical admission. A written estimate is provided where admission is required.
The questions that come up on the day of diagnosis.
Ask your question →No. Walk as normally as the pain allows, from the start. Early mobilisation is safe, does not increase the risk of the clot travelling, and significantly reduces long term swelling. Elevate the leg when you are sitting still.
At least three months. If the clot was provoked by something temporary such as surgery, treatment often stops there. If it was unprovoked, or there is an ongoing risk factor, longer or indefinite treatment may be safer, and that is a balance between clot and bleeding risk.
Generally yes, once treatment is established and symptoms have settled, but discuss timing with your doctor. On any long journey move regularly, drink water and wear compression.
The clot damages the valves inside the vein, and around a third of patients are left with some degree of chronic swelling. Consistent compression is the most effective way to limit it, and it is worth persevering with.
Rarely. Most DVT is treated with medication, compression and walking. Procedures to remove or dissolve clot are reserved for severe cases with a badly threatened limb.
Seeing patients from across the city and beyond: read about the practice on the plastic surgeon in Surat page, or check what a written estimate covers on the costs and insurance page.
