What is thrombosis?
Deep vein thrombosis (DVT) is the formation of a clot (thrombus) inside a deep vein, usually in the legs. It is a serious condition because the clot can break loose and travel to the lungs, causing a pulmonary embolism — a potentially fatal complication.
Symptoms
The classic symptoms include:
- Swelling (oedema) in one leg, usually sudden
- Pain or tenderness in the calf or thigh
- Redness or discolouration of the skin
- A feeling of warmth in the affected area
- A hard vein you can feel
⚠️ Important: DVT can be symptom-free in up to 50% of cases. If you have risk factors, prevent it and stay alert.
Risk factors
- Long periods of immobility (long journeys, bed rest)
- Recent surgery (especially orthopaedic)
- Family history of thrombosis
- Age over 60
- Obesity
- Smoking
- Use of the contraceptive pill or hormone therapy
- Pregnancy and the postpartum period
- Cancer and chemotherapy
Diagnosis
The main test is a Doppler ultrasound of the legs, which identifies the clot and assesses blood flow. Blood tests (D-dimer) can also help.
Treatment
- Anticoagulants (heparin, warfarin, DOACs) — the main treatment
- Compression stockings
- Rest with the leg raised during the first days
- In severe cases, thrombolysis or surgery
Prevention during travel
- Stand up and walk every 1–2 hours on long journeys
- Move your feet and ankles while seated
- Drink plenty of water
- Wear compression stockings if you have risk factors
- Avoid alcohol and excessive sedatives
How the examination that detects the clot works: Doppler ultrasound.