Dizziness and Vertigo
Feelings of Unsteadiness or the Room Spinning have Multiple Causes
Jan 13, 2008
Most people have experienced that vague unsteady feeling, usually after standing up too quickly, called dizziness. And many have had that unpleasant sensation of the room spinning around, often associated with nausea. Doctors distinguish between the two symptoms, calling the first dizziness and the second vertigo.
This is a useful distinction in that vertigo is more likely to point to specific problems with balance mechanisms whereas dizziness can occur for a wide variety of reasons.
Physiology of Balance
The major centre for control of balance is in the brain stem. Input into this area comes from a number of sources. The primary source is the vestibular apparatus of the inner ear. The semicircular canals of this apparatus contain fluid and sensory cells which help control balance when the head is rotatated. The otolith organs of the vestibular apparatus contain fluid and suspended particles that tell the brain where the head is in relation to gravity.
Further input comes from the eyes, neck and limbs. All this information allows the brain to constantly monitor position in space and keep us upright. Anything that causes insult to or affects the input of information into the balance control area is likely to lead to vertigo. These can include visual disturbances, neck problems, inner ear infections or interference with blood supply to the brain stem or vestibular apparatus.
Causes of Dizziness and Vertigo
Although there is much overlap, it’s useful to divide the relevant conditions up into those which are more likely to cause vertigo and those that tend to cause dizziness.
Vertigo
- Middle ear disease: bacterial infection for example
- Trauma or disease of the vertebral artery: this artery runs either side of the spine in the neck and into the brain.
- Viral labrynthitis: a generally harmless but very distressing infectious illness. Usually much vertigo and vomiting.
- Meniere’s disease: due to raised pressure in the vestibular apparatus and associated with deafness and tinnitus
- Eighth cranial nerve problems; acoustic neuroma, herpes.
- Benign paroxysmal positional vertigo: as the name suggests not fatal but highly distressing if severe and affecting quality of life. It’s due to the presence of debris in the vestibular apparatus. A simple treatment known as the Epley manoeuvre is often effective.
- Alcohol and drugs: some people are sensitive in this regard to quite small amounts of alcohol. Some medicinal drugs can cause vertigo.
- Migraine, tumours, multiple sclerosis and stroke are possible but not common causes of vertigo.
Dizziness
Whereas most of the above causes of vertigo are conditions that directly affect the balance system, the following causes of dizziness are problems of other areas affecting the balance system indirectly.
- Syncope: overactivity of the vagus nerve due to pain or shock produces a drop in blood pressure which can result in dizziness and fainting.
- Postural hypotension: a sudden drop in blood pressure on standing up. Some people are just prone to this, in others it is caused by certain types of medication.
- Cardiac arrythmias: faulty heart rhythm for whatever reason.
- Anaemia: has the effect of decreasing oxygen availability to the brain and hence deterioration in function.
- Hypoglycaemia: lack of glucose will bring about less than adequate function in all areas of the brain including that which controls balance.
- Hyperventilation: related to anxiety. Results in a drop in brain carbon dioxide levels which may bring on dizziness.
- Drugs and alcohol: will bring on vertigo in some and just dizziness in others.
This article is for information only. If you have repeated bouts of vertigo or dizziness then consult a doctor.
Further reading
Dizziness, Vertigo and Imbalance, Friedman and Hamid, 2007
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