I had a root canal that is now infected. i now have a thrombus on the interna l jugular vein. ultra sound was done but , doctors are unsure ?

Lemierre's: There is a condition known as lemierre's disease in which a retrotonsillar abscess can extend into the bloodstream and produce thrombotic lesions of the jugular veins along with other significant problems. I cannot tell whether this is true in your case, but woudl see an ENT doctor and get diagnosed. There may be other issues.

Endodontic expertise: See an endodontist for the tooth problem. Often times they can fix the problem if the root canal was originally done by a general dentist i believe the conditions are not related so see an md also for the vascular problem!