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Lightheadedness Symptoms

Feeling "lightheaded" is a general term that means you feel close to passing out. The sensation can be unnerving, but actually serves to stop you from overexerting yourself or otherwise trying to do things your body isn't prepared to do right then. Feeling lightheaded forces you to stop, rest, and reconsider before you push yourself too far.

You might hear this condition being called dizziness, or vertigo, but that is actually a different thing and means you feel as though your surroundings are spinning.

Actual lightheadedness may also be called orthostatic hypotension, postural hypotension, disequilibrium, or pre-syncope (syncope means "fainting") [1].


  • The sensation that you cannot focus your thoughts or entirely control your movements.
  • Feeling as though you are about to pass out.
  • "Graying out," or the fading of your peripheral vision.

Who is most often affected by lightheadedness?

  • Older adults often experience lightheadedness. Almost every elderly person will have some degree of orthostatic hypotension, which means you feel lightheaded upon standing up [2].
  • However, symptoms of lightheadedness can happen to anyone who:

    • Becomes dehydrated, either through sweating or vomiting.
    • Has a drop in blood sugar, either from vomiting, medication, or simply not eating.
    • Has a drop in blood pressure, especially from medications meant to lower blood pressure or remove fluid from the body (diuretics).

When is lightheadedness most likely to occur?

  • When you stand up quickly after sitting or lying down, and your body's mechanism to adjust blood pressure does not work correctly or quickly enough.
  • While sweating heavily during hot weather or exertion.
  • During or right after any illness that has caused vomiting, with resultant dehydration and low blood sugar. *Within an hour of eating a meal, especially in an elderly person.

Is lightheadedness serious?

  • Some causes, such as dehydration or low blood sugar, are easily remedied and not serious as long as they are addressed.
  • Even moderate lightheadedness can lead to fainting and/or falling, which can cause serious injury.
  • Lightheadedness can be a serious symptom if it occurs following a head injury, recurs frequently, or is accompanied by signs of stroke or heart attack.

Lightheadedness Causes

Many conditions can have lightheadedness as a symptom. The most common are those involving dehydration, blood sugar, and blood pressure, as well as more serious causes such as a stroke or heart disease [3,4].

Most common cause types:

  • Simple dehydration, because your blood volume is reduced and your blood pressure drops.
  • Low blood sugar, which means there may not be enough energy available for the brain to function normally.
  • Going suddenly from very hot to very cold conditions, or vice versa, which makes it nearly impossible for the body to adjust quickly enough.
  • Fainting or vasovagal syncope (also known as neurocardiogenic syncope) which is a reaction to certain triggers that cause the heart rate and blood pressure to fall. Examples of these triggers are emotional distress, seeing blood, or severe pain.

Less common cause types:

  • Orthostatic/postural hypotension, especially in older adults. This means that you feel lightheaded and dizzy when you go from sitting to standing. This can simply be the result of aging, when the autonomic nervous system does not respond as quickly when you stand up, or it can be a side effect of medication.
  • Emotional causes, such as a panic attack, which leads to hyperventilation.

Less common types:

  • Heart attack or significant changes in heart rate or rhythm (arrhythmia), with its disruption of the circulation, can have lightheadedness as one of its first symptoms.
  • Stroke, which also interrupts normal circulation and especially interferes with normal brain function, often starts with lightheadedness.

8 Possible Conditions

The list below shows results from the use of our quiz by Buoy users who experienced lightheadedness. This list does not constitute medical advice and may not accurately represent what you have.

  1. 1.Normal Dizziness

    Dizziness is when one feels lightheaded, faint, woozy, weak, or unsteady.

    A few hours.

    Top Symptoms:
    dizziness, lightheadedness
    Symptoms that always occur with normal dizziness:
    Symptoms that never occur with normal dizziness:
    vertigo (extreme dizziness), racing heart beat
    Phone call or in-person visit
  2. 2.Dehydration

    Dehydration occurs when the body does not have fluid to function properly, because of decreased intake or increased losses like vomiting and diarrhea. Symptoms of dehydration include extreme thirst, dark urine, fatigue, and dizziness.

    With rehydration, symptoms resolve completely.

    Top Symptoms:
    fatigue, dizziness, vomiting or diarrhea, racing heart beat, being severely ill
    Hospital emergency room
  3. 3.Hyperventilation Syndrome

    In hyperventilation syndrome, one can experience shortness of breath and often a person breaths fast and heavily. There is usually no physical problem causing these symptoms, and symptoms are often caused by anxiety, stress or emotions. Next to shortness of breath, one can experience symptoms of chest pain, palpitations or tingling in hands, feet and face. These symptoms occur commonly as attacks.

    Chronic with relapses

    Top Symptoms:
    anxiety, shortness of breath, dizziness, racing heart beat, chest pain
    Symptoms that always occur with hyperventilation syndrome:
    rapid, deep breaths
    Symptoms that never occur with hyperventilation syndrome:
    shortness of breath after a few stairs
    Primary care doctor
  4. 4.Stroke or Tia (Transient Ischemic Attack)

    A stroke is a medical emergency. Strokes happen when blood flow to the brain is stopped.


    Top Symptoms:
    dizziness, leg numbness, arm numbness, new headache, stiff neck
    Symptoms that never occur with stroke or tia (transient ischemic attack):
    bilateral weakness
    Emergency medical service

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  5. 5.Iron Deficiency Anemia

    Anemia is a condition in which the body does not have enough healthy red blood cells, which deliver oxygen. Iron deficiency anemia occurs when the body does not have enough iron. Iron helps make red blood cells.

    Resolves with treatment

    Top Symptoms:
    fatigue, headache, shortness of breath, dizziness, heavy menstrual flow
    Primary care doctor
  6. 6.Vasovagal Syncope

    Vasovagal syncope is one of the most common causes of fainting. Vasovagal syncope occurs when the body overreacts to certain triggers, such as the sight of blood or extreme emotional distress. The body coordinates a sudden drop of heart rate and blood pressure, causing reduced blood flow to the brain and a brief loss of consciousness.

    No treatment is needed.

    Top Symptoms:
    lightheadedness, brief fainting episode, having fainted multiple times, fainting after standing for a long time, fainting episode after a specific trigger
    Symptoms that always occur with vasovagal syncope:
    brief fainting episode, having fainted multiple times
    Phone call or in-person visit
  7. 7.Hypertrophic Cardiomyopathy

    Hypertrophic cardiomyopathy (HCM) is a disease in which the heart muscle (myocardium) becomes abnormally thick (hypertrophied). This happens sometimes as a result of long-term elevated blood pressure, and sometimes without any particular reason. The thickened heart muscle can make it harder for the heart to pump blood.

    Hypertrophic cardiomyopathy is a life-long condition, as the heart walls are permanently enlarged.

    Top Symptoms:
    fatigue, shortness of breath, dizziness, racing heart beat, shortness of breath on exertion
    Primary care doctor
  8. 8.Orthostatic Syncope (Fainting)

    Orthostatic syncope refers to a type of loss of consciousness caused by rapidly standing up from a sitting position, and not enough blood reaches the head. This can cause a person to pass out, but then come back to consciousness without lasting effects.

    1/3 of people report experiencing similar episode within 3 years.

    Top Symptoms:
    lightheadedness, brief fainting episode, dizziness and lightheadedness before passing out, fainting after standing up, fainting for the first time
    Symptoms that always occur with orthostatic syncope (fainting):
    brief fainting episode, fainting after standing up
    Phone call or in-person visit

Lightheadedness Treatments, Relief and Prevention

Seek immediate treatment in the emergency room or call 911 if you experience lightheadedness along with:

Schedule an appointment for:

  • Episodes of lightheadedness that begin soon after you start a new medication.
  • Episodes of lightheadedness that recur and seem to have no specific cause.

Remedies that you can try at home:

  • First, lie down with your feet up.
  • Then try a glass of water for rehydration, or a glass of orange juice to raise blood sugar if it is low. Symptoms should clear within 15 minutes. If they do not, you should seek medical attention right away.
  • Always go slowly from sitting to standing.
  • Wear support stockings.
  • Drink plenty of fluids, but avoid alcohol – it is dehydrating.
  • Use small doses of caffeine throughout the day, as it tends to keep blood pressure from dropping.
  • Keep cool! Hot baths and otherwise high temperatures cause blood vessels to dilate and blood pressure to drop, inducing lightheadedness.

FAQs About Lightheadedness

Here are some frequently asked questions about lightheadedness.

Will dehydration cause lightheadedness?

Yes, moderate to severe dehydration can cause lightheadedness. If you do not have sufficient blood volume, which can be caused by not drinking enough to replace liquid lost to sweat and urine, it can be challenging for your body to pump blood with adequate pressure up to your brain. This lack of sufficient blood flow, especially when standing, can cause lightheadedness.

Why do I feel lightheaded when I stand up?

You can feel lightheaded when you stand up if you have not had adequate hydration, are bleeding, or have been lying down for a long time and suddenly stand up. Your body has to increase blood pressure by pumping harder and constricting blood vessels to provide adequate blood flow to the brain.

Why does anxiety cause lightheadedness?

Anxiety can cause lightheadedness through a variety of mechanisms, most notably though severe hyperventilation which lowers the carbon dioxide (CO2) in the blood, which can cause tingling in the fingertips and mild lightheadedness. Additionally, a fear response can cause a vasovagal reaction which can lead to lightheadedness and even fainting by both slowing the heart rate and vasodilation.

Can lightheadedness be a sign of low blood pressure?

Yes, lightheadedness is often a sign of low blood pressure (hypotension). The low blood pressure causing lightheadedness can be caused by a variety of illnesses or medications. Shock, surprise, or anxiety can cause a sudden dilation of blood vessels in the body lowering blood pressure, which can cause fainting.

What are the differences between dizziness and lightheadedness?

Dizziness is a condition in which one's equilibrium is upset. This can occur when an individual is unable to catch their balance, as is often the case when someone consumes excessive amounts of alcohol or feel the room may be spinning around them. If it is an inner ear canal problem, this may lead to a diagnosis of vertigo [5]. Lightheadedness is more so a feeling of confusion or inability to focus on a particular item and often described as near-fainting. Vision may change, one may feel weak in the knees, and, generally, the room will not be spinning. Many people use the terms dizziness and lightheadiness interchangeably and why it is important to be more descriptive when discussing with your healthcare provider.

Questions Your Doctor May Ask About Lightheadedness

  • Q.Have you been feeling more tired than usual, lethargic or fatigued despite sleeping a normal amount?
  • Q.Did you faint?
  • Q.Do you notice your heart beating hard, rapidly, or irregularly (also called palpitations)?
  • Q.Have you experienced any nausea?

If you've answered yes to one or more of these questions, try our lightheadedness symptom checker to find out more.

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Lightheadedness Symptom Checker Statistics

  • People who have experienced lightheadedness have also experienced:

    • 8% Nausea
    • 6% Fatigue
    • 5% Headache
  • People who have experienced lightheadedness had symptoms persist for:

    • 41% Less Than a Day
    • 25% Less Than a Week
    • 17% Over a Month
  • People who have experienced lightheadedness were most often matched with:

    • 54% Dehydration
    • 27% Hyperventilation Syndrome
    • 18% Normal Dizziness
  • Source: Aggregated and anonymized results from visits to the Buoy AI health assistant (check it out by clicking on “Take Quiz”).

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  1. Post RE, Dickerson LM. Dizziness: A Diagnostic Approach. American Family Physician. 2010;82(4):361-368. AAFP Link.
  2. Gupta V, Lipsitz LA. Orthostatic Hypotension in the Elderly: Diagnosis and Treatment. The American Journal of Medicine. 2007;120(10):841-847. NCBI Link.
  3. Blahd Jr WH, Husney A, Romito K. Dizziness: Lightheadedness and Vertigo. University of Michigan: Michigan Medicine. Updated September 23, 2018. UofM Health Link.
  4. Can You Recognize a Heart Attack or Stroke? NIH News in Health. Published August 2014. News in Health Link.
  5. Lightheaded? Top 5 Reasons You Might Feel Woozy. Harvard Medical School: Harvard Health Publishing. Updated August 13, 2018. Harvard Health Publishing Link.