Why Do You Feel Dizzy? Common Causes of Dizziness Explained

Feeling dizzy can be unsettling. One moment you may feel perfectly normal, and the next you may feel lightheaded, unsteady or as if the room is spinning.

Dizziness is common and often has a relatively simple explanation, such as dehydration, standing up too quickly or a medication side effect. But in some cases, dizziness can be connected to an inner-ear problem, migraine, heart condition or a neurological emergency.

The important thing is understanding what kind of dizziness you are experiencing and whether it comes with other warning signs.

What Does Dizziness Actually Mean?

“Dizziness” can describe several different sensations.

Some people use the word when they feel lightheaded, as though they might faint. Others mean vertigo, which creates the sensation that they or the room is spinning.

Dizziness can also involve feeling off-balance or unsteady while walking. Nausea, sweating, trouble walking and ringing in the ears can sometimes occur alongside dizziness or vertigo.

Because the word covers several different symptoms, the exact sensation can provide doctors with useful clues about its possible cause.

1. Dehydration

One of the common causes of dizziness is dehydration.

When the body loses more fluid than it takes in, dehydration can develop. This may happen because of heavy sweating, vomiting, diarrhea, fever or simply not drinking enough fluids.

Dehydration can cause lightheadedness and may be particularly relevant during exercise, physical work or prolonged activity in hot conditions.

This has also become a relevant question following recent reports about Lionel Richie. TMZ reported that doctors were investigating possible slight dehydration after the singer checked into a St. Louis hospital following his August 29 performance. That report does not establish dehydration as a confirmed diagnosis.

2. A Sudden Drop in Blood Pressure

Some people become dizzy when they stand up suddenly after sitting or lying down.

This can happen when blood pressure drops after a change in position, a condition commonly called postural or orthostatic hypotension.

The result may be a brief feeling of lightheadedness, weakness or even fainting. The NHS advises people who repeatedly experience dizziness or fainting associated with low blood pressure to seek medical advice.

Moving more slowly when getting out of bed or standing up can help reduce the risk of sudden dizziness.

3. Inner-Ear Problems and Vertigo

The inner ear plays an important role in balance. Problems affecting the inner ear can therefore cause dizziness or vertigo.

One common cause is benign paroxysmal positional vertigo, commonly called BPPV. It can produce a spinning sensation when certain movements of the head trigger symptoms.

Other inner-ear conditions include labyrinthitis, vestibular neuritis and Ménière’s disease. Some of these conditions can also cause hearing problems or ringing in the ears.

If the sensation feels like the room is spinning rather than simply feeling faint, vertigo may be involved.

4. Medication Side Effects

Certain medications can cause dizziness as a side effect.

This can include medicines that affect blood pressure or other medications that influence the nervous system or balance.

If dizziness begins after starting a new medicine or changing the dose of an existing medicine, it is worth discussing the symptom with a healthcare professional. Do not stop a prescribed medication on your own without medical advice.

5. Low Blood Sugar

Low blood sugar can also cause dizziness or lightheadedness, particularly in people with diabetes who use medications that lower blood glucose.

Other symptoms can occur at the same time, depending on how low blood sugar becomes.

If someone with diabetes repeatedly experiences dizziness or other symptoms associated with low blood sugar, they should discuss the episodes with their healthcare team.

6. Migraine

Migraines are another possible cause of dizziness.

Some people can experience dizziness or balance problems with migraine, sometimes even when a typical headache is not the dominant symptom.

Because dizziness has many possible causes, recurring episodes should be evaluated rather than automatically attributed to migraine.

7. Motion Sickness

Traveling in a car, airplane or boat can trigger dizziness and nausea when the brain receives conflicting information about movement from the eyes and balance system.

Motion sickness is generally temporary and improves when the triggering movement stops.

However, severe or persistent dizziness that occurs outside situations involving motion deserves medical attention.

8. Illness, Heat and Physical Exertion

Dizziness can occur while someone is sick or physically exhausted.

The NHS lists dehydration, heat exhaustion and some illnesses among potential causes of dizziness. Physical exertion can also increase fluid loss through sweating, particularly in hot environments.

Resting, moving to a cooler environment and replacing fluids may help in mild cases, but severe symptoms should not be ignored.

9. Stress and Anxiety

Stress and anxiety can sometimes be accompanied by dizziness or a feeling of lightheadedness.

The NHS lists stress and anxiety among possible causes. However, because dizziness can have many physical causes, persistent or unexplained symptoms should not automatically be blamed on anxiety.

10. Heart and Circulation Problems

In some cases, dizziness or lightheadedness can be associated with problems involving the heart or circulation.

MedlinePlus notes that serious causes can include abnormal heart rhythms and heart attacks, particularly when dizziness occurs alongside symptoms such as chest pain, a racing or irregular heartbeat, shortness of breath or fainting.

These symptoms require urgent medical evaluation.

When Is Dizziness an Emergency?

Most episodes of dizziness are not caused by life-threatening conditions. But sudden dizziness combined with certain other symptoms can signal a medical emergency.

A stroke is one important example.

The CDC lists sudden dizziness or loss of balance among possible stroke symptoms, particularly when accompanied by trouble seeing, weakness or numbness on one side of the body, confusion or difficulty speaking.

The CDC recommends remembering B.E. F.A.S.T.:

• B — Balance: Sudden loss of balance or coordination
• E — Eyes: Sudden vision changes
• F — Face: Facial drooping
• A — Arms: Sudden weakness or numbness
• S — Speech: Trouble speaking or understanding
• T — Time: Call emergency services immediately

Stroke treatment is time-sensitive, so these symptoms should never be ignored.

Other Warning Signs You Should Not Ignore

Emergency medical attention may also be necessary if dizziness occurs with:

• Chest pain
• Severe shortness of breath
• Fainting or loss of consciousness
• Severe or sudden headache
• Seizures
• Significant weakness
• Difficulty moving an arm or leg
• Major changes in vision or speech
• A serious head injury
• Persistent vomiting or inability to keep fluids down
• Severe confusion

If these symptoms appear suddenly, seek emergency medical care rather than waiting to see whether the dizziness disappears.

What Should You Do When You Feel Dizzy?

If you suddenly become dizzy, safety comes first.

Sit or lie down until the sensation passes. Avoid standing up quickly, and move slowly when you begin walking again.

The NHS also recommends drinking fluids, getting enough rest and avoiding potentially dangerous activities while dizzy, including driving, climbing ladders or operating heavy machinery.

If dizziness keeps returning, becomes worse or occurs with other symptoms, make an appointment with a healthcare professional.

How Do Doctors Find the Cause?

There is no single test for dizziness because the possible causes are so varied.

A healthcare professional may ask when the dizziness started, whether it happens when you move or stand up, how long episodes last and what other symptoms occur.

Depending on the situation, doctors may check blood pressure, heart rhythm, hearing, balance and walking. Additional testing, including imaging, may be considered when a more serious cause such as a stroke or head injury is suspected.

The treatment depends entirely on the underlying cause.

The Bottom Line

Dizziness is a symptom, not a diagnosis.

It can be caused by something relatively straightforward such as dehydration, a sudden blood-pressure drop, medication or motion sickness. It can also come from inner-ear disorders, migraine or other medical conditions. In rare but serious situations, sudden dizziness can be part of a stroke or another emergency.

The key is to pay attention to how the dizziness feels, when it happens and what other symptoms appear alongside it.

And if dizziness is sudden and severe — especially when combined with weakness, speech or vision problems, chest pain, fainting or severe headache — don’t wait for it to pass. Seek emergency medical help.

This article is for general informational purposes and is not a substitute for diagnosis or treatment from a qualified healthcare professional.