What are signs of having a blood clot?

Blood clots where: most blood clots in young people are venous blood clots not arterial. venous blood started from the leg as DVT ,the symptoms unilateral swelling, severe calf tenderness,and tightness.the clot could travel to the lung and caused PE,which could be deadly .the symptoms from PE chest pain, and short of breath that low oxygen saturation. discovered early could be treatable, missed can caused death.

Serious condition: pain, swelling out from the clot, change in circulation (color and fluid changes). but they can be fatal if they break off so, evaluation in a medical emergency room is recommended cannot say in your particular case, but generally,