- Balance Disorders Slideshow
- Take the Vertigo Quiz
- Tinnitus Slideshow: Why Are My Ears Ringing?
- Patient Comments: Dizziness - Diagnosis
- Patient Comments: Dizziness - Causes
- Patient Comments: Dizziness - Standing Up
- Patient Comments: Dizziness - Treatment
- Dizziness facts
- Introduction to dizziness (feeling dizzy)
- What are some common causes of dizziness?
- Low blood pressure
- Postural or orthostatic hypotension
- High blood pressure
- Endocrine diseases
- 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 vertigo diagnosed?
- How is dizziness treated?
Quick GuideBalance Disorders: Vertigo, Motion Sickness, Labyrinthitis, and More
The heart is an electrical pump and for it to work, the electrical conduction system must be operating properly to stimulate the heart muscle to squeeze in a coordinated fashion and pump blood to the body. The heart muscle itself must be strong enough to pump blood, and the valves in the heart must work properly to allow blood to flow in the direction intended during contraction.
- Conduction disturbances: Electrical conduction disturbances may make the heart beat too quickly (tachycardia) or too slowly (bradycardia), and either of these situations may result in an inadequate blood supply to the brain, causing dizziness or lightheadedness.
- Cardiomyopathy: Dizziness is also a symptom of cardiomyopathy (cardio=heart +myo=muscle + pathy= disease), a disease of the heart muscle, resulting in muscle that doesn't squeeze effectively. Most commonly the weakness is due to atherosclerotic heart disease or ischemic cardiomyopathy (ischemic=decreased blood supply), in which the heart muscle itself doesn't get enough blood supply to work properly. Other non-ischemic cardiomyopathies may be due to diabetes, alcohol use, and viral infections.
Vasovagal syncope is a common cause of dizziness, lightheadedness, and fainting. The vagus nerve is overstimulated and causes the body's blood vessels to dilate and the heart to slow down. This anti-adrenaline effect decreases the ability of the heart to pump blood upward toward the brain. Without blood flow, the brain turns off. In Victorian England, young ladies' sensibilities were easily offended causing a vasovagal episode called a swoon.
Some people faint at the sight of blood. Some parents faint when their child gets immunized. Some medical students faint at their first autopsy. Many types of emotional and physical stressors can overstimulate the vagus nerve, causing dizziness, lightheadedness, and at times fainting (passing out).
Fainting is not normal. If a person is unconscious, the emergency medical system should be activated (call 911 if available), and medical care should be sought.