Dizziness (vertigo) is one of the most general symptoms those doctors encounter. There are many reasons of this condition but we can assume that there is always “something wrong” with vestibular system (organ in inner ear maintaining balance and movement) or with brain. Given how our brain is dependent on oxygen supply and internal environment, dizziness may emerge even by diseases of the cardiovascular system and disruption of internal environment of the organism.
Any brain disease may manifest with dizziness, especially conditions associated with cerebral edema and increased intracranial pressure. Possible causative factors include injuries (most commonly brain concussion), brain tumors, brain infections (including meningitis), stroke, epileptic seizures, etc.
Diseases or irritation of vestibular system
This pair organ is located deep within skull bone in inner ear. It consists of three semicircular canals that are anatomically very closely connected with the auditory apparatus and vestibulocochlear nerve. Disorders include inflammatory processes in the proximity of above mentioned structures, such as middle ear infections (otitis media), local brain tumors, vestibular schwannoma (also known as acoustic neuroma), injuries and alcohol influence. We should also not forget Meniere's disease and simple motion sickness.
This group of diseases comprises atherosclerosis of cerebral arteries followed with their narrowing and general lack of oxygen in brain tissue that causes brain disorders including possible dizziness. Narrowing can, however, affect also big neck arteries that lead blood in the head. There are two carotid arteries and two vertebral arteries. Carotid artery narrowing can cause dizziness, especially when it is bilateral, and it also elevates risk of ischemic stroke occurrence. Vertebral arteries are located near cervical spine and they merge into one artery feeding the brainstem. Vertebral arteries tend to narrow when bending head backward. This means that when affected person tries to look up and bends his or her head, he or she begin to suffer from vertigo or sudden unconsciousness. This condition is known as vertebrobasilar insufficiency and it is very common in the elderly.
Many commonly used medications cause dizziness as a side-effect or by overdose. We can mention for example antidepressants and sleeping pills. Of course, this also covers the effects of addictive substances including alcohol that influences both brain and vestibular system. Intoxications with the majority of toxic substances causes vertigo as well, I have for example composed an article dedicated to carbon monoxide poisoning.
Changes in blood pressure
Deficiency of red blood cells means less oxygen transported to the brain and that leads to various complaints including dizziness. Dizziness is a typical symptom of anemic syndrome.
Inner environment disorders
Dizziness may be caused by changes in concentrations of ions (mainly sodium and chloride), dehydration, accumulation of metabolic waste products in liver failure or renal failure (acute or chronic), hypoglycemia, or hyperglycemia in untreated diabetes. Even temperature change of organism may be followed by subsequent dizziness (like fever).
The elderly usually suffer from general atherosclerosis including cerebral arteries; sometimes even their carotid arteries are narrowed. This fragile system can be easily disrupted by other cause like infections, mineral imbalance, blood pressure changes etc.
Given the range of possible causes, complex examination is usually needed. A patient suffering from vertigo shall be physically examined by a neurologist, ECG should be checked and blood pressure measured. Blood tests are also important, for example blood minerals levels, renal parameters, liver tests, blood count, CRP (infectious processes in the body), etc.
Best imaging method used for anatomical area of head including inner ear is computed tomography or magnetic resonance imaging. Carotid arteries may be examined by ultrasound. Heart function may be investigated by echocardiography and lungs by functional respiratory tests including spirometry. If we do not find a clear cause, when visual disturbances are present, it is wise to recommend ophthalmologic examination. Further diagnostic approach depends on outcome of previously mentioned examinations.