What are nonneurologic causes of dizziness?
Patients complaining of dizziness often have subjective descriptions that are unreliable and inconsistent.
A patient complaining of vertigo does not mean the cause is a vestibular disorder, and a patient who denies vertigo may have a vestibular disorder.
Lightheadedness is a very nonspecific symptom, but if accompanied by a near-loss of consciousness, suggests diminished cerebral blood flow, possibly cardiac in origin.
Many patients have hyper- or hypotension that can cause lightheadedness, cardiac arrhythmias, imbalance, and difficulty walking.
Lightheadedness can be seen with metabolic disorders, medication side effects, or drug interactions, hence all patients should be evaluated for polypharmacy.
Hypoglycemia may cause dizziness in severe diabetics. Many older people limit their fluid intake to avoid frequent bathroom trips and then become dehydrated.
Dehydration may cause lightheadedness due to loss of volume. Severe rhinosinusitis can cause dizziness that the patient may interpret as positional vertigo, if the problem is exacerbated by positional changes.
