Blood clots. A blood vessel can be blocked by an embolus. This can be a little mass of debris that moves with the bloodstream. Or it may be blocked by a thrombus. It is a blood clot. Carotid artery sickness: A blockage or narrowing while in the arteries giving your Mind. https://www.sgvascularctr.com/a-comprehensive-approach-to-lymphoedema-treatment-a-vascular-surgeons-perspective/