Feeling unsteady or dizzy can be caused by many factors such as poor circulation, inner ear disease, medication usage, injury, infection, allergies, and/or neurological disease. Dizziness is treatable, but it is important for your doctor to help you determine the cause so that the correct treatment is implemented.
Dizziness can be described in many ways, such as feeling lightheaded, unsteady, giddy, or feeling a floating sensation. Vertigo is a specific type of dizziness experienced as an illusion of movement of one’s self or the environment.Your sense of balance is maintained by a complex interaction of the following parts of the nervous system:
- The inner ear (also called the labyrinth), which monitors the directions of motion, such as turning, rolling, forward-backward, side-to-side, and up-and-down motions.
- The eyes, which monitor where the body is in space (i.e., upside down, right side up, etc.) and also directions of motion.
- The pressure receptors in the joints of the lower extremities and the spine, which tell what part of the body is down and touching the ground.
- The muscle and joint sensory receptors (also called proprioception) tell what parts of the body are moving.
- The central nervous system (the brain and spinal cord), which processes all the information from the four other systems to maintain balance and equilibrium.
The symptoms of motion sickness and dizziness appear when the central nervous system receives conflicting messages from the other four systems.
Vertigo: Vertigo usually is due to an issue with the inner ear. The common causes of vertigo are (in order):
- Benign Positional Vertigo: Vertigo is experienced after a change in head position such as lying down, turning in bed, looking up, or stooping. It lasts about 30 seconds and ceases when the head is still. It is due to a dislodged otololith crystal entering one of the semicircular balance canals. It can last for days, weeks, or months. The Epley “repositioning” treatment by an otolaryngologist is usually curative. BPV is the commonest cause of dizziness after (even a mild) head injury.
- Meniere’s disease: An inner ear disorder with attacks of vertigo (lasting hours), nausea, or vomiting, and tinnitus (loud noise) in the ear, which often feels blocked or full. There is usually a decrease in hearing as well.
- Migraine: Some individuals with a prior classical migraine headache history can experience vertigo attacks similar to Meniere’s disease. Usually there is an accompanying headache, but can also occur without the headache.
- Infection: Viruses can attack the inner ear, but usually its nerve connections to the brain, causing acute vertigo (lasting days) without hearing loss (termed vestibular neuronitis). However, a bacterial infection such as mastoiditis that extends into the inner ear can completely destroy both the hearing and equilibrium function of that ear, called labyrinthitis.
- Injury: A skull fracture that damages the inner ear produces a profound and incapacitating vertigo with nausea and hearing loss. The dizziness will last for several weeks and slowly improve as the other (normal) side takes over. BPV commonly occurs after head injury.
- Allergy: Some people experience dizziness and/or vertigo attacks when they are exposed to foods or airborne particles (such as dust, molds, pollens, dander, etc.) to which they are allergic.