Every person reading this has experienced dizziness at some point or another in their lives, either when they take those first tenuous steps off a roller coaster or after getting up too quickly after a relaxing nap. With the vast majority of people having experienced this sensation while awake, it brings up an interesting question: Will you wake up dizzy if you were sleeping on a spinning object?
Short Answer: Yes, because the equilibrium organs still function while we sleep, and the superficial causes of dizziness will immediately be present when you wake up and open your eyes.
The Science of Dizziness
While everyone knows what dizziness feels like, many people still don’t full understand what causes dizziness. One reason for this is that dizziness can be caused by many different factors. The most common source of dizziness is an inner ear problem, also known as vertigo, which can be acute or chronic. Basically, your balance system (vestibular system), which is negatively affected by dizziness, is controlled by the inputs from three different systems – your eyes, inner ear and sensory nerves.
Your eyes report what they see to your brain, establishing your “place” in the world. Combined with that are the inputs from your sensory nerves, which are found all over your body, and help to define the movement and physical location of your limbs and body parts. Finally, your inner ear comes into play, which is the most important aspect.
Your inner ear contains something called the labyrinth, which is where the action happens. Inside the labyrinth are three semicircular canals, called the horizontal, superior and posterior semicircular canals. Each of these canals is filled with a fluid called endolymph. When the head is moving, the fluid moves as well, and the receptors in those canals relay the message of movement to the brain.
This inner-ear information is combined with what the eyes are telling the brain to ensure that what we see isn’t out of focus. When these two streams of information don’t match up properly, particularly with what our sensory nerves are telling us about the movement and placement of our limbs, vertigo (or a sense of dizziness) can be experienced. The dizziness experienced from rapid jerking or spinning movements is explained by this system of information processing.
However, those aren’t the only causes of dizziness. You may also have infections that can affect the nerves of the vestibular system, poor blood circulation, migraines, anxiety, dehydration, low blood pressure, and various other chronic diseases. If you suffer from one of these conditions, it could also explain dizziness upon waking – even if you weren’t sleeping on a spinning object!
Can We Get Dizzy While We Sleep?
This is a particularly challenging question because “dizziness” requires consciousness and self-awareness to report, which is somewhat impossible while sleeping. Furthermore, when we are asleep, our eyes are closed and the amount of visual information being relayed to the brain is significantly reduced. Therefore, while the inner ear and sensory nerves may be relaying information to the brain that the body and head are moving, there is no visual input to contradict or confuse this information.
As soon as our eyes open, a third input gets thrown into the mix, which is when the confusion in the brain begins. Due to momentum of the fluid in our semicircular canals, even if the spinning suddenly stops, the fluid may still be moving, telling the brain that the head is moving in a certain direction. However, the eyes will report that the head is not, in fact, moving, and dizziness may be immediately experienced upon waking.
Another interesting outcome could be if the spinning is constant while a person is sleeping. Assuming constant angular speed, the inner ear and sensory organs would eventually acclimate to the new direction or angular acceleration. When the eyes opened, however, they would detect movement and changes in that acceleration, which might not be what is being reported by the inner ear and sensory nerves. As a result, dizziness could also occur in this situation.
For example, when you are driving in a car at 50 miles per hour on a perfectly smooth road, with your eyes closed, the inner ear and sensory organs will get used to the sensation of moving that quickly, in that particular direction. When you open your eyes, however, and see the world whipping by at a fast speed, it may be temporarily confusing for the brain, which can result in dizziness or motion sickness.
At any time of the day, provided that you are awake to see it happen, any confusion between your eyes, ears and body can cause dizziness. Not everyone is as susceptible to dizziness, but no one is fully immune from it either. Now that we understand that even an unconscious person on a spinning object can wake up and feel dizzy, it brings us to a final important question: Who is falling asleep on a spinning object in the first place? Have you ever tried to snatch a nap on a roller coaster?