While dizziness and vertigo are often seen as interchangeable experiences, the underlying causes and physiology of each differ significantly. Let’s take a deeper look and see what causes these two conditions and figure out how they’re different from each other.
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Decoding Dizziness
We’ve all felt dizzy before. It’s a word we use to describe a variety of subjective states that all feel roughly the same, but can have quite different causes. Generally speaking, when we say we feel dizzy, we’re referring to a feeling of being lightheaded, unsteady, or off-balance. It’s often associated with a sensation of spinning or being unable to hold still.
Why Do We Get Dizzy?
Dizziness has a wide variety of causes. People most frequently report feeling dizzy when they experience acute episodes of low blood pressure, often caused by orthostatic hypotension. This is just a scientific way of describing the process of blood either flowing out of your brain, or not flowing to your brain quickly enough, when you stand up or change position quickly.
Blood is constantly being pumped through your veins and arteries by your heart, delivering oxygen to your brain and other parts of your body to help them function. When your body’s demand for oxygen increases or changes rapidly, your heart may take just a fraction of a second too long to ramp up its beating to maintain your blood pressure, and so your brain may experience a brief period of oxygen deprivation. This sensation of lightheadedness often causes trouble maintaining balance or a sense of direction, and that’s why you feel dizzy when you stand up too quickly, especially after sitting or lying down for a prolonged period.
Other causes of dizziness include dehydration, motion sickness, side effects of medication, anxiety, low blood sugar, heart problems, or anemia. While most of these involve the same or similar method of oxygen deprivation described above, some do have causes similar to those of vertigo.
Motion sickness, for example, is caused by your body’s inability to calibrate and coordinate your physical sensations to produce an accurate sense of direction. This is often caused by the vestibular system in your ear providing information that doesn’t match what your eyes or proprioceptors are conveying, or vice versa.
Your vestibular system consists of three fluid-filled canals in your inner ear that detect and convey information about your head’s movement within the three axes of physical space: up or down, left or right, and forward or backward. Your eyes constantly convey information to your brain about how your body is moving through space and how objects move around you. Your proprioceptors are nerves in your joints and muscles that relay information to your brain about how your limbs and body are moving together. When any of these signals don’t match up, you may feel a type of dizziness that is a bit closer to vertigo than that caused by oxygen deprivation.
What Is Vertigo?
As any doctor or student in online ABSN programs will tell you, vertigo is a very specific type of dizziness that occurs when the vestibular system is malfunctioning. It causes your body to feel like you are spinning or moving in unpredictable directions, even when you might be standing completely still.
How Is It Different From Dizziness?
The sensation of vertigo is often persistent and very distressing compared to dizziness or even motion sickness. While intense motion sickness can often cause mild or even strong nausea and other unpleasant physical sensations, vertigo is often accompanied by a strong fear of the unknown, given your brain’s inability to explain the feelings of movement when your eyes or proprioception are clearly conveying that no movement is occurring at all.
Why It Happens
Vertigo is caused when there is a problem with the fluid-filled tubes in your inner ear, or the part of your brain that interprets the information conveyed by these tubes, the vestibular nerve. The most common cause is Benign Paroxysmal Positional Vertigo (BPPV). This occurs when small calcium carbonate crystals known as otoconia, responsible for helping your brain sense acceleration and the position of your head, become dislodged and move from the tubes that detect linear movement into tubes that detect different types of movement. This sends confusing signals to your vestibular nerve, causing it to misinterpret the position of your head.
Vertigo can also be caused by Meniere’s Disease, a buildup of fluid in the inner ear, which can result in tinnitus or hearing loss, or vestibular neuritis, the inflammation of the vestibular nerve, usually caused by viral infections. Other causes include labyrinthitis, migraines, traumatic head injuries, and acoustic neuroma, a type of non-cancerous tumor in the inner ear.
The Importance of Understanding the Difference
While some people might be tempted to use the term vertigo casually, it is often a misnomer; this kind of casual use of medical terminology can, over time, erode the seriousness with which we should treat symptoms that may indicate quite serious illnesses. Hopefully, knowing the difference between dizziness and vertigo will help more people from making this mistake.