Deep vein thrombosis is a blood clot in a deep vein, most often in the leg, and it can become dangerous if part of the clot travels to the lungs.
Symptoms may include swelling in one leg, calf pain, warmth, redness, or tenderness, though some people have only mild symptoms or none at all.
Imaging helps when a clot is suspected from one-sided leg swelling or pain, especially after surgery, long travel, immobility, cancer, or pregnancy-related risk.
Venous Doppler ultrasound is usually the first imaging test because it can show whether a deep vein is blocked by clot and how extensive it is.
Treatment often includes blood thinners, activity advice, and follow-up, with more urgent intervention needed in selected severe cases.
This entry explains the condition. The next step is having a radiologist interpret your specific scan, not a general definition.