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

High blood pressure, or hypertension, is known as the "silent killer" since it often has no symptoms, even if blood pressure readings are markedly elevated. On occasion, a person may complain of headache, nausea, or dizziness, although the complaints don't necessarily correlate with the degree of blood pressure elevation.

However, if the blood pressure is elevated and the person has symptoms, there is a need to bring the blood pressure under control relatively quickly. The more severe the symptoms, the quicker blood pressure control needs to be achieved. For example, if a person is having chest pain or stroke symptoms associated with high blood pressure, the blood pressure needs to be controlled immediately.

Dizziness is a common complaint in persons with diabetes, and may be caused by low blood sugar (hypoglycemia), high blood sugar (hyperglycemia), or autonomic dysfunction (see previously).

• Hypoglycemia or low blood sugar (hypo=low +glyc=sugar =emia=blood) occurs because of an inadequate amount of glucose in the blood. A person with diabetes can develop hypoglycemia from an inadequate amount of food intake, or from taking too much medication (insulin or oral tablets), which results in low blood sugar levels. In this situation the person experiences dizziness or lightheadedness because the brain lacks glucose to function properly. Persons with diabetes and their families need to recognize the symptoms of hypoglycemia, including dizziness, sweating, confusion, and coma as treatment needs to be given immediately. Oral sugar-containing foods or a glucagon injection may be life-saving for the patient.
  
  
• Hyperglycemia (hyper=high +glyc=sugar +emia=blood) also causes dizziness. High blood sugar levels occur because there is not enough insulin available to allow cells to use glucose for energy metabolism. (Interestingly, brain cells do not need insulin to use glucose.) High blood sugars cause a variety of metabolic responses in the body leading to dehydration, anaerobic metabolism, and changes in the acid-based balance. This may result in a life-threatening condition referred to as diabetic ketoacidosis.