1. Balance Disorders Slideshow
2. Take the Vertigo Quiz
3. Tinnitus Slideshow: Why Are My Ears Ringing?

Medical Author:

Benjamin Wedro, MD, FACEP, FAAEM

Benjamin Wedro, MD, FACEP, FAAEM

Dr. Ben Wedro practices emergency medicine at Gundersen Clinic, a regional trauma center in La Crosse, Wisconsin. His background includes undergraduate and medical studies at the University of Alberta, a Family Practice internship at Queen's University in Kingston, Ontario and residency training in Emergency Medicine at the University of Oklahoma Health Sciences Center.

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Medical Editor:

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

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In this Article

• Introduction to dizziness (feeling dizzy)
• What are some common causes of dizziness?
• Low blood pressure
• Postural or orthostatic hypotension
• High blood pressure
• Diabetes
• Endocrine diseases
• Hyperventilation
• Heart conditions
• Vasovagal syncope
• Dizziness and vertigo
• What are the symptoms experienced when a person feels dizzy?
• When should I call the doctor for dizziness?
• How is dizziness diagnosed?
• How is dizziness/vertigo diagnosed?
• How is dizziness treated?
• Dizziness At A Glance
• Patient Comments: Dizziness - Diagnosis
• Patient Comments: Dizziness - Causes
• Patient Comments: Dizziness - Standing Up
• Patient Comments: Dizziness - Treatment
• Dizziness (Dizzy) Index

In individuals who are dehydrated or anemic, blood pressure readings may be normal when they are lying flat, however, the lack of fluid is unmasked when they stand up quickly. The lack of blood to the brain causes dizziness and lightheadedness. This feeling may pass in a few seconds as the body adapts. However, if dehydration or medications (for example, beta blockers) prevent the body from reacting by constricting blood vessels and increasing the heart rate, the dizziness may persist to the point at which the patient passes out (faints, syncope).

Some diseases are associated with an inability to compensate for changes in body position (autonomic dysfunction). Normally when a person stands, blood vessels contract to increase blood pressure slightly,  and the heart rate increases to push blood up to the brain (pushing against gravity). In autonomic dysfunction, a person may become dizzy when they move from a lying position to sitting or standing up.  Examples of these diseases include diabetes, Addison's disease, or Parkinson's disease).

Orthostatic hypotension is a common symptom with Shy-Drager syndrome. Shy-Drager syndrome is a rare disease in which the autonomic nervous system degenerates and cannot provide the routine control mechanisms for the body including heart rate, blood pressure, and bowel and bladder function.