Brief Answer:
Veins thrombosis has been ruled out with an ultrasound.

Detailed Answer:
Hello!

Thank you for the query.

Veins thrombosis is dangerous only if located in deep veins. In such case you may get symptoms like calf pain, calf hardness and swelling, pain while walking or flexing the foot.
As you have had Dopplers veins ultrasound done which has ruled this possibility out, no reason to consider your symptoms as thrombosis.

Lower leg and foot swelling can be caused by an injury of this area, soft tissues infection or just veins insufficiency (this should be diagnosed in the Dopplers ultrasound).
If the other leg is also somehow swelled, heart issues can be the case.

I suggest you to have an x-ray of affected area at first. If there is also some redness and you have fever or pain, infection can be the case. Antibiotic may be necessary.

Hope this will help. Feel free to ask further questions.
Regards.

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