When a person has a dizziness disorder, they will often feel off balance when on their feet. Imbalance or unsteadiness can be as simple as just feeling “off”, or slightly uncertain of your balance. As imbalance worsens, you might begin to fear that you will fall, and you may bump into doorways or have to touch counters in the house to steady yourself. A more severe imbalance can cause you to stagger from side to side when walking or have to walk with your feet wide apart to maintain balance. Most people will start using support aids like a cane or walker when this stage is reached. In the most severe cases, you might be unable to walk unless someone is physically holding you up. People with this very severe imbalance will be confined to a wheelchair or their bed.
The vestibular system senses movement, and it responds to the feeling of motion by sending out a response: reflexes that make your eyes, head, arms, and legs move. Their movement is coordinated so that it exactly counterbalances the motion your head made. Imagine walking on a log over a stream. You try to keep your head very still and hold your arms out to steady yourself. If your head senses a tilt, your arms swing up and down and your legs bend and straighten enough to counter that. This is an automatic, subconscious reflex system.
If your vestibular system malfunctions, it senses motion when no movement has happened. This sets off reflexes that would be perfect if movement had occurred but are a problem when the movement is an illusion. You might flail your arms and step to the side, even though your head is steady. Some vertigo disorders can cause a person to tip over like a log to the floor. Even though they were standing steadily, the inner ear signaled that they were falling over, so they when they attempt to counterbalance, they fall in the opposite direction by mistake.
It is also possible for you to feel off balance and yet not be terribly dizzy. You might feel dizzy only when on your feet, and never when seated or lying down. This type of imbalance can result from losses of proper feedback to the balance system from the body. As you walk, your inner ears send out counterbalancing reflexes to the limbs and neck that keep your head steady. These reflexes are refined and calibrated by feedback loops. For example, the ankles and knees are able to sense how much they are flexed and straightened, and the skin of the foot senses the pressure of your weight against the ground as the foot moves. If your feet are numb, something that commonly arises with aging and nerve diseases like neuropathy, or if you have had joint replacements that remove the sensors that feel the joints flex and extend, you will not get the proper feedback and so the reflexes may be too much or too little.
Next, we’ll consider the problem of falls.