Dizziness is a common symptom bringing patients to doctor’s offices or emergency rooms. There are numerous causes of dizziness and finding the one affecting a patient can sometimes be challenging, especially if common sense and a methodical approach is overlooked. Without knowing the exact cause, patient may continue to suffer, even more so with added frustration and anxiety from lack of a proper diagnosis.

What is dizziness?

Dizziness is not a precise term or a concept. It is also not a disease; it is just a symptom. Patients use the same word for a variety of problems. In every case of dizziness, the first question to ask the patient is: what exactly do you mean by dizziness? Many patients resist this type of questioning, stating that they are “you know, just dizzy.” In such situations, giving a few options to the patient (lightheadedness, or sense of motion, or confusion, or unsteadiness) is helpful. Following are some of the answers and some conditions that may be relevant:

A: Lightheadedness or a feeling of faint
Conditions: Syncope (many causes), seizure disorder, migraine

B: Sense of motion like I am on a boat, or the earth is moving, or spinning sensation
Conditions: Vertigo (many causes), seizure disorder, migraine

C: Spacing out, confusion, unresponsiveness
Conditions: Seizure disorder, drugs

D: Difficult to describe feeling, difficult to find words for it, “out of the world feeling”
Conditions: Seizure disorder, drugs

E: Unsteadiness and loss of balance
Conditions: Neuropathy, many brain disorders (e.g., NPH, Parkinsonism)

F: Fogginess
Conditions: Mental disorders (many), dementias

Dizziness is any or a combination of the above. It is important to figure out the type of feeling from the list above, so that appropriate next step can be taken to make a diagnosis.

How is the cause of dizziness found?

Patient’s description of symptoms is the most important data to make a diagnosis of dizziness. Analysis of the following questions can make a tentative diagnosis in most cases:

A: Nature of dizziness: What do you mean by dizziness (see above)?
B: Timing of dizziness: When did it start? How often it happens? How long it last?
C: Triggers: If any.
D: Associated symptoms: If any.

Tests are not needed to rule out every possible cause of dizziness, instead a proper test, if required, can be done. Unfortunately though, this logical methodology is frequently ignored and, like a cookbook, a set of tests is ordered. Instead of figuring out the exact cause of dizziness, patients are left with added frustration about the test findings, usually unrelated to their symptoms.

What is the most common cause or type of dizziness?

Feeling of lightheadedness or a faint feeling, including fainting, is the most common type of dizziness. It is caused by any condition that may significantly drop blood pressure, e.g., syncope. Vertigo is also quite common.

What is syncope?

Syncope is just a word for fainting, in this case from very low blood pressure. There are many causes of syncope, or many types of syncope.
(Read More about Syncope)

What is vertigo?

Vertigo is false sense of motion. The perceived motion can be of any of the multiple kinds, like a sense of ground moving underneath, on-a-boat feeling, head turning, things around are moving, or a frank spinning sensation. It is the feeling we used to enjoy in young age when we turned around and around and then stopped, left with a feeling of moving around and loss of balance. It is not a diagnosis, just a symptom. There are many conditions that can cause vertigo; a common one is called Benign Paroxysmal Positional Vertigo (BPPV). Because of its common nature, many times physicians just use the term vertigo while talking about BPPV. For more detail, review the page on vertigo.
(Read More about Vertigo)

How does body keeps our balance?

It is a complicated subject but an outline is provided here. Generally speaking there are 4 systems running in parallel to help keep our balance. They are as follows:

A: Vision: This is the easiest system to understand. Our eyes help us navigate through any space. We can navigate without eyes, and people with limited vision do, but with difficulty. They rely on the other three systems. If one of the other systems is weak, and our vision gets blur, we can easily get dizzy or unsteady. This is the reason that patients with numb feet from neuropathy may easily loose their balance in dark spaces.

B: Proprioception: Basically this system is composed of receptors and sensory nerves in our feet and joints sending signals about our position, through the spinal cord, to our brain. Adjustments are made in muscle groups or body parts based upon this information. For example, if a standing person bends down, the front parts of feet and joints sense the motion and send signals to brain through the spinal cord. There are many conditions that may affect this system, from receptors in our skin, nerves, spinal cord, to the brain itself. This is an important system for the body, and if it is defective, the other three systems cannot fully maintain body’s balance.

C: Vestibular system: Vestibular system is a structure deep in our ears. It is complex; it is intriguing, and fascinating, and not completely understood yet. Following is a general introduction. To keep our balance in all kind of postures we assume or activity we perform, our brain always wants to know the direction and the type of movement (e.g., rotation or linear) and, in reference to our body, where our head is. The information from this system helps to maintain balance, especially if our vision is compromised.

A pair of three bony semi-circular canals or tubes is placed, one set on each side, deep inside the ear. These three tubes in a way are aligned with three axes, x, y, and z, acting as sensors. They are filled with jelly like fluid with one end slightly dilated. Close to that are two separate smaller but similar compartments, called utricle and saccule, with similar structural detail. Floor of each dilated area of the canals, utricle and saccule, is lined with thin hair like cells (or hair cells) in erect position. These hair cells can bend in different directions if there is a movement in the fluid. Suspended on top of these cells are tiny calcium carbonate crystals, like a weight. The crystals are bound together by glue like material, which keeps them together.

Every head movement we make is either in x, y, or z-axis, or any of their combinations. Due to their inertia, every head motion generates a tiny movement of the crystals suspended in the fluid, which creates a tiny wave in the fluid. The fluid movement creates tiny bend in the underneath hair cells. The mechanical movement of hair cells is converted in an electrical signal that travels to the brain. The receptors in semicircular canals sense movement, especially rotational movement. The utricle and saccule sense vertical and linear movements, which probably also includes gravity. Because of exact replica of three tubes on either side, with opposite orientation, any movement of hair cells on one side is associated with a similar movement on the other, but in opposite direction. The system is placed at about 30-degree angle tilted upwards because in erect body posture our head is tilted forward by about 30 degrees from the earth’s horizontal plane. This way the x axis stays within earth’s horizontal plane.

It is a beautifully designed engineering marvel operating through multiple scientific principles including solid-state physics, fluid dynamics, electrochemistry, electronics, complicated biochemistry, and even much more that we do not yet understand. It is precise enough to sense every bit of head motion, but modulated enough to not overshoot or undershoot and send just the right signal to the brain. Constantly reading these signals, brain adjusts our posture, muscle tone, and the direction of gaze to let us flawlessly move around, dance, run, jump, or dive.

This system works well if both left and right sides are in sync; any amount of asynchrony sends mixed messages. If a person is stationary and this apparatus sends an asymmetric signal, it is read as a sense of motion, a false sense of motion, which we call vertigo. The type and severity of vertigo depends upon the location and the extent of the problem. There are numerous conditions that may affect this system.

D: Cerebellar system: When we imagine a brain, two large half-globes come to mind, which is called cerebral cortex, the largest part of the brain. Underneath, in the back of our head and above the neck is another area called cerebellum. Cerebellum is much smaller but it has more cells or neurons than rest of the brain. It is also an intriguing part of the brain in a sense that we have little understanding of why these many cells are there. Compared to the rest of the brain, our understanding of what cerebellum does is quite limited. One aspect of cerebellum is known; its disease causes unsteadiness and dizziness.

One function of cerebellum is to streamline our movements. Imagine someone is throwing an imaginary punch to a friend’s face, bringing the fist very close to the face with no intention of a hit. This may not happen if cerebellum on that side is defective, and the fist may land on the face. Cerebellum is particularly good on adjusting when to stop a movement, of hands, legs, or even vocal cords. What cerebellum does is especially important in extreme situations, such as walking on a rope or during gymnastics. In usual routine life situations, one may even loose a chunk of cerebellum and still walk around without difficulty.

These four systems are continuously at work, complimenting each other and helping us with our physical abilities.

What should I do if I have dizziness?

Talk to your doctor and be specific about your symptoms. Try to describe exactly what you feel. The above description may help to pick up the right words. Some causes of dizziness require further investigations, and some require consultation with a specialist. Your PCP can help to figure this out.

Where can I get more information about dizziness?

Many topics related to dizziness are covered on this site, e.g., syncope, vertigo, and seizure disorder. Click the appropriate page for reading.