Q: What causes dizziness when you change your position?

Krishna: Benign paroxysmal positional vertigo or BPPV occurs when crystals move from one part of the inner ear to another, disrupting signals to the brain.

When a person experiences vertigo, s/he may feel as though his or her surroundings are spinning or moving around them.

To understand this condition, we have to first understand the balancing system of the ear

The inner ear contains two different structures:

• The cochlea converts sound vibrations into nerve impulses, which the brain interprets as sound.
• The vestibular system provides information about the body’s position and plays a vital role in balance and coordination. It consists of the bony labyrinth, the membranous labyrinth, and the semicircular canals.

BPPV occurs when calcium carbonate crystals, which usually appear in the membranous labyrinth, move to one or more of the semicircular canals.

BPPV usually occurs when calcium carbonate crystals, or otoconia, that sit in a gravity-sensing part of the ear called the utricle become dislodged. They then move to the fluid-filled, motion-sensing semicircular canals.

If enough otoconia accumulate in any of the canals, it can disrupt the fluid movement the canals use to detect head motion.

The semicircular canals do not usually react to gravity. However, otoconia move along with gravity. As a result, when clumps of otoconia build up in the semicircular canals, they can make the motion-sensing fluid move when it should not. This sends an incorrect message to the brain that the head is moving.

When the brain compares this false message from the inner ear with information from the other senses and organs, it cannot make them match, so it recognizes it as a spinning sensation.

This miscue causes nystagmus, a condition where the eyes move uncontrollably back and forth or up and down, making it seem like someone’s surroundings are spinning.

Moving the head can trigger vertigo because the solid crystals respond to gravity. The following head positions and movements can trigger vertigo in people who have BPPV:

• turning the head
• lying on the side of the head
• rolling over in bed
• bending the head forward
• leaning the head back

BPPV is a common cause of vertigo. BPPV occurs when calcium carbonate crystals move from the membranous labyrinth to the semicircular canals in the ear.

Intense vertigo can make you nauseous or so unsteady you can’t drive or walk. It feels like you or objects around you are:

• Floating.
• Spinning.
• Swaying.
• Tilting.

People with vertigo can feel these things even while going up and down in lifts, escalators or aeroplanes. 

A few conditions may also cause or influence BPPV, including:

• head injury
• inner ear infections or diseases
• laying down for a long time
• osteoporosis
• diabetes
• intubation
• reduced blood flow
• blockage of the anterior vestibular artery
• ear surgery
• migraines

Although this condition is not life threatening, it can cause significant discomfort and interfere with a person’s daily life.

BPPV can go away on its own once the body reabsorbs the calcium carbonate crystals. However, if symptoms do not improve on their own, people can choose from several effective treatment options.

Epley Maneuver to Treat BPPV Vertigo

If you want more information, you can read these articles and research papers by clicking on the links given below: 

• Benign paroxysmal positional vertigo. (2017).
  https://rarediseases.org/rare-diseases/benign-paroxysmal-positional...
• Kaur, J., & Shamanna, K. (2017). Management of benign paroxysmal positional vertigo: A comparative study between Epleys maneuver and Betahistine [Abstract].
  https://www.ncbi.nlm.nih.gov/pubmed/28723599
• Parfenov, V. A., et al. (2017). Effectiveness of betahistine (48 mg/day) in patients with vestibular vertigo during routine practice: The VIRTUOSO study.
  https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0...
• Pérez-Vázquez, P., & Franco-Gutiérrez, V. (2017). Treatment of benign paroxysmal positional vertigo. A clinical review.
  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6002633/
• Wang. Y.-H., et al. (2019). Benign paroxysmal positional vertigo — recommendations for treatment in primary care.
  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6572671/

                                                                        **************

PS:

Orthostatic hypotension — also called postural hypotension — is a form of low blood pressure that happens when you stand up from sitting or lying down. Orthostatic hypotension can make you feel dizzy or lightheaded, and maybe even cause you to faint.

Orthostatic hypotension may be mild, and episodes can last for less than a few minutes. However, long-lasting orthostatic hypotension can signal more-serious problems, so it's important to see a doctor if you frequently feel lightheaded when standing up.

The most common symptom is lightheadedness or dizziness when you stand up after sitting or lying down. Symptoms usually last less than a few minutes.

Orthostatic hypotension signs and symptoms include:

• Lightheadedness or dizziness upon standing
• Blurry vision
• Weakness
• Fainting (syncope)
• Confusion
• Nausea

Occasional dizziness or lightheadedness may be fairly minor — triggered by mild dehydration, low blood sugar or overheating. Dizziness or lightheadedness may also happen when you stand after sitting for a long time. If these symptoms happen only occasionally, there's likely no cause for concern.

It's important to see your doctor if you have frequent symptoms of orthostatic hypotension because they can signal serious problems. It's even more urgent to see a doctor if you lose consciousness, even for just a few seconds.

(Please note that the answers for the questions  given here on this network for  medical conditions are only for information purpose and are not  professional medical advices. You should not seek any medical advice on the internet. Please consult a good qualified medical doctor for any serious medical condition - Krishna)