Causes of Dizziness

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While “dizziness” is a word very commonly used by both doctors and non-doctors, from a medical standpoint it is a very imprecise term. This is because people can mean several different when they say they are “dizzy.” Depending on what kind of dizziness they are talking about, the medical significance of the symptom, and the steps a doctor should take in evaluating it, can differ substantially.

So if you and your doctor want to know why you have dizziness, the first thing you will both have to do is to identify what, exactly, you mean by “dizziness?”

The Two Kinds of Dizziness

There are two general kinds of dizziness that produce two distinct kinds of symptoms, and these kinds of dizziness tend to have entirely different sets of causes.

The two kinds of dizziness are lightheadedness and vertigo.

With lightheadedness, a person feels faint, or woozy and weak, and may feel as if they are about to pass out. Lightheadedness may occur as discrete episodes, or may be persistent. It is often accompanied by severe unsteadiness and an urge to sit or lie down, as well as other symptoms that may include buzzing in the ears, tunnel vision, sweating, and/or nausea. And if a person experiencing severe lightheadedness fights the urge to sit or lie down, he or she very well might experience syncope (an episode of loss of consciousness).

In contrast, vertigo is a sensation that makes you feel as if the environment is moving around you when it is not, and is often described as "the room is spinning." People with vertigo often feel as if they themselves are whirling and off-balance, and they want to grab on to something to keep themselves from being flung to the ground. They may also have severe nausea or vomiting along with vertigo.

Evaluating Lightheadedness

It is not too unusual for people to experience a brief episode of lightheadedness from time to time, usually when they stand up too quickly. These brief episodes are caused by a momentary drop in blood pressure. Normally, the cardiovascular system adjusts to this change in position in a second or two, and the episode passes. Fleeting episodes of lightheadedness when getting up too quickly are generally not anything to be concerned about, as long as you take precautions to avoid falling.

However, if lightheadedness persists or if episodes come on frequently, or (especially) if syncope occurs, a medical evaluation is needed. There are many potentially significant medical conditions that can produce serious episodes of lightheadedness, and it is important to figure out the cause.

Some of the more common causes of lightheadedness include:

  • dehydration, for instance, with the flu, with vomiting or diarrhea, or after exercise without adequate fluid replacement)
  • blood loss (which may occur without your knowing it, especially with gastrointestinal bleeding)
  • anxiety or stress
  • the use of alcohol, tobacco or certain drugs
  • various cardiac arrhythmias
  • other cardiac conditions such as heart failure
  • dysautonomia
  • vasovagal syncope

Because the potential causes of lightheadedness are so many and so varied, evaluating people who have this symptom often presents a challenge to doctors. However, because some of the potential causes are dangerous, it is important to make the correct diagnosis.

Generally, if a doctor takes a thorough medical history and performs a careful physical exam, strong clues will be uncovered that should point to the best kinds of medical tests to perform to pinpoint the cause.

Evaluating Vertigo

Vertigo is most often caused by a problem with the inner ear such as an ear infection or Meniere's disease, but it may also be caused by conditions affecting the brainstem, such as multiple sclerosis or stroke.

Vertigo is much less common than lightheadedness, and because often has a discrete, identifiable underlying medical cause, this is a symptom that should always be evaluated by a doctor. If you should have vertigo accompanied by double vision, numbness, tingling or muscle weakness, the probability of a serious neurological problem becomes much higher, and the situation ought to be treated as an emergency. You should get immediate medical help for such episodes.

After your doctor performs a careful medical history and physical examination, it is likely that an imaging study, such as a magnetic resonance imaging (MRI) test, may be needed to pin down the diagnosis. The treatment of vertigo is often very effective, but depends on making an accurate diagnosis of the underlying cause.

A Word From Verywell

Figuring out why a person is experiencing dizziness requires, first of all, identifying which "kind" of dizziness a person is experiencing. Whether the dizziness is best described as lightheadedness or vertigo is important in directing the medical evaluation.

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Article Sources

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