Dr. Steven Silverman retired as of March 2026. Drs. Ulloa and Arosemena of Vascular Wellness Institute are now available and taking new patients. Same office, same friendly faces, and a new lens on your vascular care!

Medically Reviewed By:

2026-05-01

Dizziness & Syncope

Also Known As: fainting or near-fainting
Dizziness and syncope (fainting or near-fainting) can have many causes, ranging from benign to life-threatening. Among the most important and treatable vascular causes are carotid artery disease — which can cause TIAs with sudden dizziness, vision changes, or near-fainting — and subclavian steal syndrome, in which reversal of vertebral artery flow during arm exercise produces posterior circulation symptoms including vertigo, dizziness, and syncope. Accurate diagnosis requires a thoughtful vascular evaluation.

Dizziness & Syncope — Vascular Causes, Evaluation & Treatment in Sarasota & Bradenton


Dizziness and fainting have many causes, and most of them are not serious. But when these symptoms happen alongside other signs of poor circulation — arm fatigue, headaches, or vision changes — a vascular cause is worth investigating. Sometimes narrowing in the carotid arteries or the arteries to the brain can reduce blood flow enough to cause these kinds of episodes, particularly in people with cardiovascular risk factors.

Vascular Causes of Dizziness

The vascular system supplies the brain with the oxygen-rich blood it needs to function. Any significant compromise of cerebral blood flow — even transiently — can produce dizziness, lightheadedness, vision changes, speech difficulty, or loss of consciousness. Two important vascular causes evaluated by our team include carotid disease causing TIAs with anterior circulation symptoms (sudden one-sided weakness, speech problems, vision loss in one eye) and subclavian steal syndrome causing posterior circulation symptoms (vertigo, bilateral vision blurring, ataxia, drop attacks) triggered by arm exercise.

Carotid Artery Disease and TIA

A transient ischemic attack (TIA) — often called a mini-stroke — is a brief episode of neurological dysfunction caused by temporary blockage of blood flow to the brain, most commonly from a small clot or plaque fragment breaking off from the carotid artery. TIA symptoms include sudden dizziness, one-sided face or arm numbness or weakness, difficulty speaking, or sudden vision loss in one eye. A TIA is a medical emergency — 10–15% of patients have a major stroke within 90 days. Immediate evaluation and treatment (CEA, TCAR, or carotid stenting) dramatically reduces stroke risk.

Subclavian Steal Syndrome

Subclavian steal syndrome produces posterior circulation symptoms — dizziness, vertigo, ataxia, visual changes — triggered by arm use, particularly overhead activities. Blood is diverted retrograde from the basilar artery down the vertebral artery to supply the arm beyond a stenosed subclavian artery. The symptoms characteristically relate to arm activity and are reproduced by arm exercise testing. Treatment with subclavian artery stenting eliminates the steal and resolves symptoms.

Evaluating Dizziness in Sarasota & Bradenton

Our vascular surgeons evaluate patients with dizziness and TIA symptoms with carotid duplex ultrasound — the front-line test for carotid stenosis — and subclavian artery assessment. CT angiography of the head and neck provides detailed vascular imaging. Close coordination with neurology ensures appropriate stroke-risk stratification and management.

SYMPTOMS

  • Episodes of dizziness, lightheadedness, or near-fainting
  • Transient loss of consciousness (syncope)
  • Vertigo or balance disturbance
  • Visual blurring or double vision
  • Dizziness or neurological symptoms triggered by arm exercise (subclavian steal)
  • Brief episodes of speech difficulty, facial drooping, or unilateral weakness preceding dizziness (TIA)

RISK FACTORS

  • Carotid artery disease
  • subclavian artery stenosis
  • vertebrobasilar insufficiency
  • atrial fibrillation
  • cardiac arrhythmia
  • orthostatic hypotension
  • dehydration
  • medications (antihypertensives, diuretics)

DIAGNOSIS METHODS

  • Duplex Carotid and Vertebral Ultrasound +

    Screens for carotid stenosis and reversal of vertebral artery flow indicating subclavian steal syndrome.

  • Blood Pressure Both Arms +

    Blood pressure difference >15 mmHg between arms suggests subclavian stenosis as the cause.

  • CT Angiography +

    Detailed anatomy of the carotid and vertebral circulation when intervention is planned.

TREATMENTS

RELATED SYMPTOMS

FREQUENTLY ASKED QUESTIONS

  • How do I know if my dizziness is cardiac, neurological, or vascular? +

    Distinguishing the cause requires evaluation by specialists. Vascular causes of dizziness tend to produce focal neurological symptoms (one-sided weakness, vision changes, speech problems) or relate to arm exercise (subclavian steal). Cardiac causes (arrhythmia, valve disease) tend to cause global lightheadedness with palpitations. A vascular evaluation including carotid duplex ultrasound is a critical part of the diagnostic workup for any patient with unexplained dizziness or syncope.

  • If I had a TIA, how soon do I need to see a vascular surgeon? +

    Immediately — within 24–48 hours. A TIA is a warning sign of impending stroke. The risk of stroke is highest in the hours to days immediately following a TIA. If significant carotid stenosis is identified, surgery or stenting may be recommended within days to prevent the anticipated stroke.

  • Can neck surgery cure my dizziness? +

    If significant carotid stenosis is the cause of your TIA symptoms, carotid revascularization (CEA or TCAR) reduces your risk of future stroke by 50–65%. For subclavian steal syndrome, subclavian stenting resolves symptoms in the vast majority of patients. However, not all dizziness is vascular in origin — accurate diagnosis is essential before recommending any intervention.