What is the difference between dizziness and vertigo?

Dizziness is the umbrella word. Vertigo is one kind of dizziness, "a feeling that you are spinning or moving, or that the world is spinning around you," in MedlinePlus's words. Lightheadedness is "a feeling that you might faint." Vertigo usually comes from the inner ear and sometimes from the brain; lightheadedness more often from blood pressure, fluids or blood sugar.

Can dehydration cause dizziness?

Yes. MedlinePlus lists dehydration from vomiting, diarrhea, fever or other conditions as a cause of lightheadedness. Dizziness with vomiting or diarrhea where you cannot keep fluids down needs urgent care.

Can a sinus infection cause dizziness?

A blocked nose can make you feel muzzy, but the clearer link is labyrinthitis, "a viral infection of the inner ear that usually follows a cold or flu," which causes vertigo. The NHS lists ear infections among the causes that improve once the illness is treated.

What blood tests check for the cause of dizziness?

Most people need none. When a clinician tests, glucose, a blood count, sodium and B12 are the ones that read the blood-based causes, and an ECG checks the heart rhythm. Tests are more useful in people with diabetes, high blood pressure or several medicines.

When is dizziness an emergency?

Call 911 for sudden dizziness or loss of balance with a drooping face, an arm that drifts down, slurred speech, trouble seeing or a sudden severe headache, and note the time the symptoms started. Dizziness with chest pain, an irregular heartbeat, shortness of breath, fainting, a head injury, a seizure, new weakness, or a high fever, severe headache or very stiff neck also needs 911.

What causes dizziness? Lightheaded, spinning or off balance

Q: What causes dizziness?

The common causes are dehydration, standing up too quickly, medicines, inner ear problems such as BPPV and labyrinthitis, anxiety and migraine. Low blood sugar, anemia and heart rhythm problems are less common, and stroke is a rare but urgent cause.

Q: Why would I feel lightheaded?

The usual reasons are dehydration from vomiting, diarrhea or fever, getting up too quickly, medicines that lower blood pressure, and low blood sugar. Overbreathing during anxiety can do it too. Lightheadedness with chest pain, an irregular heartbeat, shortness of breath or fainting needs 911.

Q: Why do I get dizzy when I stand up?

Usually because blood pressure drops for a moment as you stand, called orthostatic hypotension. Dehydration, water pills and blood pressure medicines make it more likely, and it becomes more common with age. Clinicians diagnose it when blood pressure falls by more than 20 in the top number or 10 in the bottom number within three minutes of standing.

The distinctions

01
Lightheaded, spinning and off balance are three different symptoms
Feeling about to faint usually points to blood pressure, fluids, blood sugar or the heart. A spinning feeling (vertigo) usually points to the inner ear, and sometimes the brain. Feeling unsteady on your feet points to nerves, muscles, eyes or medicines. Saying which one you have, and what sets it off, does more than any blood test.
02
Blood tests rarely explain dizziness
In one large group of people with dizziness, lab results explained it in only 26 of 4,538 people. The inner ear causes are found by questions and a bedside exam, and the dangerous causes, stroke and heart rhythm problems, by an exam, a scan or an ECG. Blood tests matter for a few causes: low blood sugar, anemia and low sodium.

Dizziness is a word for three different feelings: lightheaded, as if you might faint; vertigo, a sense that you or the room is spinning; and off balance, unsteady on your feet. ¹² Most dizziness has an everyday or harmless cause: not enough fluid, standing up too fast, a medicine, or an inner ear problem such as benign paroxysmal positional vertigo (BPPV, brief spinning set off by moving your head). ²³ Anxiety, migraine, low blood sugar, anemia (too few red blood cells) and heart rhythm problems are other causes, and a stroke is a rare but urgent one. ¹³⁴ What sets the dizziness off, and how long it lasts, tells a clinician more than a blood test does. ³

When to get help now

Most dizziness passes and is not dangerous. These signs can mean a stroke, a heart problem or another emergency, and they need help now, even if they ease.

Call 911 or your local emergency number

Sudden dizziness or loss of balance with a drooping face, an arm or leg that is weak or numb, or slurred speech ⁴
Sudden trouble seeing, or new double vision ²⁴
A sudden severe headache with no known cause ⁴
Chest pain, shortness of breath, or an irregular or racing heartbeat ²
Fainting, or staying confused or drowsy for more than a few minutes ²
New weakness, sudden trouble walking, or not being able to move an arm or leg ²⁴
A head injury, a seizure, a high fever, a severe headache or a very stiff neck, or not being able to keep fluids down ²

See a doctor soon, the same day if you can

Dizziness for the first time, or a first attack of constant spinning that lasts for hours, even with no other signs: a stroke can look like an inner ear problem ²³
Dizziness that will not go away or keeps coming back ¹
New hearing loss, ringing in the ears, or blurred vision ¹
Dizziness that started after a new prescription medicine ¹
Lightheadedness every time you stand, or a fall ³⁵
Dizziness with tiredness or pale skin, which can go with anemia ¹

LifeFrom can't examine you or assess a symptom. If something feels seriously wrong, trust that and get care rather than waiting on a test.

Lightheaded, vertigo or off balance: which one is it?

People use "dizzy" for very different experiences, and clinicians used to sort dizziness into four groups: vertigo, presyncope (nearly fainting), disequilibrium (unsteadiness) and light-headedness. ³ A 2017 American Family Physician review notes that people describe the feeling inconsistently, so clinicians now lean on two questions instead: is it set off by something, such as standing up or turning your head, and does it come in episodes or never let up? ³ Both are easy to answer at home. Write down what you were doing when it started and how long it lasted.

What it feels like	The word for it	Common causes	What checks it
About to faint, woozy, vision greying out	Lightheaded	Dehydration, standing up fast, blood pressure medicines, low blood sugar ²	Blood pressure lying and standing, glucose, a blood count, an ECG ³⁵
You or the room spinning, often with nausea	Vertigo	BPPV, labyrinthitis, vestibular neuritis, Ménière disease, migraine, rarely stroke ²³	Questions and a bedside exam such as the Dix-Hallpike test; a scan if stroke is possible ³
Unsteady on your feet, worse in the dark	Off balance	Inner ear problems, medicines, nerve damage in the feet, low B12 ¹⁸	An exam of walking and feeling in the feet; B12 ⁸⁹

0.6%of people with dizziness had a lab result that explained it26 of 4,538 patients. Most causes are found by the history and a bedside exam. Source: American Family Physician, 2017. ³

What can cause it, most likely first

Ranked from most to least likely in adults in general. The order shifts with age, sex and history: in older adults medicines and blood pressure drops move up, migraine is more common in women aged 20 to 50, and anyone with diabetes medicines or heart disease has those causes higher on the list. ³⁵

01
Not enough fluid, heat, alcohol or a skipped mealEverydaycommon
Dehydration from vomiting, diarrhea, fever or heat is a common cause of lightheadedness. ² Alcohol, caffeine and cigarettes can make dizziness worse, which is why the NHS advises avoiding them while dizzy. ¹ If the feeling lifts with fluids and food, there is usually nothing more to find. Dizziness with vomiting where you cannot keep fluids down needs urgent care. ²
02
Standing up too fast (orthostatic hypotension)Everydaycommon
When you stand, blood pressure dips for a moment, and if it does not recover quickly you feel lightheaded for a few seconds; some people faint. ⁵ A drop of more than 20 in the top number or 10 in the bottom number within three minutes of standing is called orthostatic hypotension, and it becomes more common with age. ⁵ Dehydration, water pills, long bed rest and some medicines for blood pressure, Parkinson's disease and depression make it more likely. ⁵ No blood test checks it; blood pressure measured lying down and then standing does.
03
MedicinesEverydaycommon
In older adults seen in primary care, medicines were implicated in 23% of dizziness, and taking five or more medicines raises the risk. ³ Common culprits are blood pressure medicines, seizure medicines, benzodiazepines (sedatives) and sedating antihistamines. ³ The NHS lists dizziness after starting a new prescription as a side effect to raise with a clinician. ¹ Do not stop a prescribed medicine on your own; the prescriber can adjust it safely.
Sodium
A low sodium, below the lab's range (MedlinePlus gives 136 to 144 mEq/L), can come with water pills and causes confusion, headache, tiredness and weakness. ¹¹ See electrolytes explained.
04
Inner ear problems: BPPV, labyrinthitis and vestibular neuritisMedicalcommon
BPPV causes "a spinning feeling that occurs when you move your head," for example when rolling over in bed. ² Labyrinthitis and vestibular neuritis, inflammation of the inner ear or its balance nerve usually after a viral illness, cause vertigo that settles over a few days. ²³ The 2017 review warns that a stroke can mimic these, so a first attack of constant spinning deserves a same-day check, and spinning with any trouble walking, speaking or seeing means 911. ³⁴ Ménière disease causes vertigo with hearing loss or ringing in one ear. ²³ No blood test checks the inner ear. A bedside exam does, and BPPV is often treated in the clinic with a head-turning maneuver (the Epley maneuver) that works in about 70% of people the first time. ³
05
Anxiety, panic and overbreathingMedicalcommon
Stress and anxiety are on the NHS list of causes. ¹ Breathing too fast during anxiety or panic (hyperventilation) can make you "lightheaded, dizzy, weak, or not able to think straight," with tingling around the mouth or in the arms. ¹² Dizziness linked with anxiety or depression is often on and off at first, then more constant. ³ No blood test checks it, and a clinician rules out the other causes first. If low mood comes with thoughts of harming yourself, call or text 988.
06
Migraine (vestibular migraine)Medicalless common
Migraine can cause episodes of vertigo lasting five minutes to 72 hours, with or without a headache. ³ In adults it is three times more common in women and most often starts between 20 and 50, and it runs in families. ³ No blood test checks it; the pattern of episodes does. A first-ever severe, sudden headache with dizziness is a 911 sign, not a migraine to wait out. ⁴
07
Low blood sugarMedicalless common
Low blood sugar can make you "dizzy, lightheaded, confused, or irritable," shaky, with a fast heartbeat. ⁶ It mainly affects people taking insulin or diabetes pills such as sulfonylureas, and for many of them low means a reading below 70 mg/dL. ⁶ MedlinePlus lists low blood sugar among the causes of lightheadedness in general. ² See blood sugar explained.
Fasting glucose
A fasting glucose of 99 mg/dL or below is normal, 100 to 125 fits prediabetes and 126 or above diabetes. ¹⁰ A reading below 70 mg/dL during symptoms, in someone on diabetes medicines, fits low blood sugar. ⁶
HbA1c
HbA1c is average blood sugar over 2 to 3 months: below 5.7% is normal, 5.7% to 6.4% prediabetes, 6.5% or above diabetes. ¹⁰ It can look normal while short lows happen, so it is context rather than a test for lows.
08
Anemia, low iron or low B12Medicalless common
Iron deficiency anemia is one of the illnesses the NHS lists as a cause of dizziness that improves once treated. ¹ Low vitamin B12 can cause anemia and, when it lasts, nerve problems with numbness, tingling and loss of balance. ⁸ Tiredness, pale skin and breathlessness on stairs often come with anemia; see fatigue. A clinician decides on iron or B12 after a test.
Can be linked with Anemia
Hemoglobin
A low hemoglobin on the complete blood count points to anemia; the blood count then helps sort out whether low iron or low B12 is behind it. ⁸ See the CBC explainer.
Ferritin
A low ferritin points to low iron stores, the cause behind iron deficiency anemia; the reason for low iron is then looked for. ¹
Vitamin B12
A B12 below 299 pg/mL is a possible sign of deficiency on MedlinePlus's range, and a high methylmalonic acid confirms it. ⁹ See B12 deficiency.
09
Heart rhythm problemsMedicalless common
An arrhythmia (an abnormal heart rhythm) can cause dizziness and fainting, sometimes with a fluttering, pounding or skipped heartbeat. ⁷ Dizziness that comes suddenly with no trigger can have a heart or metabolic cause, and the 2017 review advises an ECG and a heart monitor when symptoms suggest heart disease. ³ See heart palpitations for more.
Electrocardiogram (ECG)
An abnormal rhythm on the ECG points to an arrhythmia; a normal ECG between episodes does not rule one out, so a Holter monitor may follow. ³
Heart rhythm
A normal rhythm recorded during a dizzy spell points away from the heart; an irregular, very slow or very fast rhythm at that moment ties the dizziness to the heart. ³⁷
10
Stroke and other brain causesMedicalrare
"Sudden trouble walking, dizziness, loss of balance, or lack of coordination" is one of the CDC's stroke warning signs. ⁴ The 2017 review warns that a stroke can cause dizziness with no other obvious sign, and that "Central etiologies often require urgent treatment." ³ No blood test checks for stroke; an emergency exam and a brain scan do, which is why sudden dizziness with any stroke sign means 911, not waiting to see. ³⁴

These are things a symptom like this can be linked with, not a diagnosis. Several can sit together, and a clinician who knows your history puts them in order for you.

Why do I get dizzy when I stand up?

A few seconds of greying out when you stand up quickly is common, especially when you are short of fluids or have been drinking alcohol. ²⁵ It happens because blood pressure dips before the body catches up. Cleveland Clinic calls the main symptom "dizziness or lightheadedness when you stand," and notes that some people faint. ⁵ It is more common after 60, and with water pills and medicines for blood pressure, heart disease, Parkinson's disease and depression. ⁵ A clinician checks it by measuring your blood pressure lying down and again after standing. ⁵

What to do in the moment is simple: sit or lie down until it passes, then get up slowly, staying seated for a few moments before you stand. ¹² Falls are the risk, so lightheadedness every time you stand, or a fall, is worth raising with a clinician, particularly if you take several medicines. ³

Dizziness and vertigo: the inner ear causes

Peripheral causes, meaning the inner ear and its nerve, are the commonest source of vertigo and are "usually benign," in the words of the 2017 review. ³ The pattern points to which one. Brief spinning set off by moving your head, such as rolling over in bed, fits BPPV. ²³ Days of spinning and feeling sick after a cold or flu fit labyrinthitis or vestibular neuritis. ¹²³ Attacks of spinning with hearing loss and ringing in one ear fit Ménière disease. ³ Continuous vertigo with any trouble walking, speaking or seeing is treated as a possible stroke until proved otherwise. ³⁴

During a vertigo attack, MedlinePlus advises keeping still and resting, and avoiding bright lights, TV and reading. ² It also advises not driving, operating heavy machinery or climbing until a week after symptoms have gone. ² If dizziness and numbness or tingling come together, see tingling in hands and feet.

Why would I feel lightheaded for no reason?

There is usually a reason, even if it is not obvious. Look first at fluids, food, alcohol, heat, sleep and any medicine started or changed in the past few months. ¹²³ Anxiety and overbreathing can cause lightheadedness with tingling lips and a racing heart that feels alarming but passes. ¹² Lightheadedness with a skipped or racing heartbeat, chest pain or breathlessness points to the heart and needs 911. ² Repeated lightheadedness with tiredness and pale skin points to anemia; see brain fog and fatigue if those are part of it.

The panel that checks these

Most dizziness needs no blood test, so a clinician picks from this list. Glucose and a blood count come first for lightheadedness, because low blood sugar and anemia are the blood-based causes; sodium is added for people on water pills, and B12 for unsteadiness or numbness. ³ Only the fasting glucose needs fasting, usually overnight. The ECG and heart rhythm entries are recordings, not blood tests, and the inner ear causes have no blood test at all.

SodiumMedicines
Fasting glucoseLow blood sugar
HbA1cLow blood sugar
HemoglobinAnemia, low iron or low B12
FerritinAnemia, low iron or low B12
Vitamin B12Anemia, low iron or low B12
Electrocardiogram (ECG)Heart rhythm problems
Heart rhythmHeart rhythm problems

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Getting a useful test

Describe the feeling in your own words: about to faint, spinning, or unsteady. ³
Note what sets it off and how long it lasts: seconds after standing, under a minute when rolling over, hours, or days. ³
Bring a full list of medicines with start dates and doses, including sleep aids and allergy pills. ³
If you have a home blood pressure monitor, take a reading lying down and again after a few minutes standing, and bring both.
Mention hearing changes, ringing in the ears, headaches, and any numbness or weakness. ¹
One result is a snapshot; see why trends beat single readings.

What may help

Most dizziness eases once the trigger is found. These steps come from NHS and MedlinePlus advice, and none replaces checking the red flags above.

Start with the everyday things

Lie down until the dizziness passes, then get up slowly. ¹
Drink plenty of fluids, especially water, and more in heat or with vomiting or diarrhea. ¹²
Avoid coffee, cigarettes, alcohol and drugs while dizzy. ¹
Do not bend down or stand up suddenly. ¹
Avoid driving, ladders and heavy machinery while dizzy, and for a week after vertigo has gone. ¹²
Ask a clinician whether a head-turning maneuver for BPPV fits your pattern; it is done or taught in the clinic. ³

No supplement is listed here. None treats dizziness. Low iron and low B12 matter only when a test shows them, and a clinician decides what to do after finding why they are low. Supplements support general wellness. They don't treat the causes above, and if a test finds one, treating that comes first. If you take medicines, are pregnant or have a health condition, check with your clinician before starting anything.

Questions to ask your clinician

Is this lightheadedness, vertigo or unsteadiness, and what does that point to?
Could any of my medicines be causing it?
Can you check my blood pressure lying down and standing?
Do I need glucose, a blood count, sodium or B12 checked?
Could this be BPPV, and can you test for it or treat it today?
Which signs would mean I should call 911?

This page is general education, not medical advice or a diagnosis. Dizziness has many causes that can overlap, and the clinician who knows your history and examines you is the one to put them in order.

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Citations

Educational context only, not medical advice or a diagnosis. Always discuss your results with a clinician.

What causes dizziness? Lightheaded, spinning or off balance, and the tests that check each

When to get help now

Lightheaded, vertigo or off balance: which one is it?

What can cause it, most likely first

Why do I get dizzy when I stand up?

Dizziness and vertigo: the inner ear causes

Why would I feel lightheaded for no reason?

The panel that checks these

Getting a useful test

What may help

Questions to ask your clinician

Work it out

Working on this?

Related symptoms

Related guides

Related markers