Why Driving Makes You Dizzy

For people who experience dizziness, many stop driving. While it is absolutely a safety concern (you shouldn't drive if you're currently dizzy), what happens when driving makes you feel dizzy? Maybe you wouldn't even call it dizzy, but you'd describe it as motion sickness or feeling car sick.

Believe it or not, there's PT for that. While most people think of physical therapy as a place you go to exercise, you might be surprised to learn that you can exercise your eyes, use movement to correct problems in your vestibular system, and even train your nervous system to have better balance and position sense. Before you can effectively treat a problem, however, it's best to understand the cause. Let's take a look at:

1. What Happens When You Drive

2. Mixed Messages While Driving

3. Reading In The Car

4. How To Treat It

What Happens When You Drive

Driving is something that many of us take for granted, but it is actually a pretty complex task. In order to drive safely, our eyes have to move in a lot of different directions. We are continually scanning the road ahead, checking our mirrors, and glancing at the speedometer.

Your proprioceptive nerves that sense position are on call too. They are sensing the position of your body telling your brain how much pressure your foot is placing on the pedal and whether your foot is angled towards the gas or the brake. Your nerves are feeling the shift of your weight to the side as you round a curve in the road. They also tell your brain that your weight is shifting back into the seat as you accelerate the car to move again after sitting at a red light.

Then there is the non-obvious but very important vestibular system. The crystals in your inner ear tell your brain that you've turned your head to the side to check your blind spot before changing lanes. They also let your brain know if you've tipped your chin up as you look into the rear view mirror.

Our brains are also hard at work judging distances between our car and another car. The brain is anticipating how quickly we need to adjust our speed to slow down for (or speed through) the yellow light ahead. Aside from the actual driving, it is trying to remember or listen for directions and thinking about all of the day-to-day thoughts we're processing at any given moment.

If all of that isn't enough, keep in mind, that this assumes a fairly simple model of driving. It doesn't include the distractions of the radio, eating while driving, or the kids arguing in the back seat.

Mixed Messages While Driving

Driving is a reasonably confusing activity to the balance centers in our brains. The brain receives mixed messages that it has to sort out to help determine what is actually happening.

For example, as you drive, your eyes looking at the road ahead tell your brain that your body is moving forward at one speed. At the same time, your peripheral vision sees things passing comparatively more quickly through the side window. The eyes are sending messages to the brain telling it that you are moving at 2 different speeds.

At the same time, your nervous system tells your brain that there is solid contact between your bottom and the seat of the car. It essentially sends a message saying, "I'm sitting still in a chair."

The vestibular system may chime in as you turn your head slightly to look at your rear view mirror and say, "We're turning to the right."

It is hard work for your brain to prioritize which message to focus on. When the brain has a hard time reconciling these mixed messages, people feel dizzy, nauseous, and/or develop a headache.

When you realize just how hard your brain is working, it makes more sense why people often complain of feeling tired after driving all day, even though they didn't do a significant amount of physical activity.

Reading In The Car

Many people who develop trouble with dizziness later in life feel a sense of frustration; that they ought to be able to read in a car without feeling sick because they always could before. Motion sickness from reading in the car, however, actually makes a lot of sense when you stop to think about it. The nerves in your body and your vestibular system tell your brain that you are moving along with the car. On a logical level as well, a person who is reading in a car knows that the car is still moving. At the same time, however, some of your nerves are telling the brain that you are sitting still, with a constant pressure of your bottom on the seat of the car.

Their eyes are painting a picture for the brain as well. The eyes are looking at a page that isn't moving. Depending on the location of where you are holding your book or device, you may or may not have any competing information from your eyes with an awareness of what is happening outside the windows.

To make matters more complicated, not only are your eyes looking at a page that likely isn't moving, but your eyes are moving repeatedly. They are tracking the words across the page and then jumping back to the other side of the page to begin reading the next line of text.

Reading also prompts an added layer of complex sensory processing in our imaginations. A person may be visualizing a picture of what they are reading, or hearing the sounds of the voices of the author or characters in their heads.

This can create a complex over-layering of information for your brain with conflicting realities, both based on physical sensory perceptions, and cognitive processing of imagined sensations.

How To Treat It

Though it may be unsatisfying, the honest answer is, "It depends." To address a symptom, it's best to treat the cause. This usually starts with an evaluation by a physical therapist who specializes in dizziness, or vestibular rehabilitation.

The therapist will help determine which systems are giving the brain incorrect information, and develop a plan to both help the system(s) function better, and help the brain process the information correctly.

If the problem is in the vestibular system, treatment frequently involves positional maneuvers to help align the crystals properly in the ear canal. It may also involve balance exercises with head movements to teach the brain to interpret changing information from the vestibular system how to adapt.

If the issue is in the way your eyes are tracking the movements around you, the treatment looks different. The therapist may assign eye exercises to help the muscles in your eyes coordinate their movements more smoothly. These visual habituation exercises help the brain practice both how to move your eyes appropriately, and to better identify when the eyes have made a mistake. If your brain recognizes the mistake, it will quickly decide to rely on the other balance systems information, instead of the system it knows is malfunctioning.

If the nerves in the body are not sensing your body position correctly, your therapist may assign a variety of balance exercises to try and fine tune the position sense in your body. If certain nerves are not functioning well due to being compressed, or getting poor circulation, they may tailor a treatment program to help optimize/restore the health of your nerves. If the nerves are permanently damaged, the therapist may help teach your brain not to rely on them and to use the information from the other systems instead.

Lastly, sometimes the brain itself is the issue. Perhaps it can't sense right and left well (see: Seeking Direction In Pain: Why Telling Right from Left Is Hard). Perhaps another condition like migraines or dysautonomia/POTS is temporarily limiting the amount of blood flow to the brain, making it harder to process information (see: POTS University).

Regardless of the reason, a skilled physical therapist can often help improve your symptoms by either rehabilitating the system that is not functioning well, or teaching you how to compensate for it.

This article is intended for educational purposes and is not intended as a replacement for individual medical advice. If you are interested in being evaluated by a licensed physical therapist for your unique case, you can click Book Online to schedule an evaluation.