Lightheadedness

Lightheadedness is the feeling of losing consciousness or fainting. If you've ever felt off, woozy, or like you're about to pass out, chances are you have experienced lightheadedness. Many people experience lightheadedness at some point despite being completely healthy.

Most causes of lightheadedness are not life-threatening. Common causes of lightheadedness, such as standing up too quickly, not drinking enough water, or breathing the air at a high altitude, resolve relatively quickly without treatment.

However, in rare cases, lightheadedness may signify a more serious medical complication like heart disease or diabetes. You should seek medical care if you experience recurrent, sudden, severe, prolonged, or unexplained lightheadedness.

This article will discuss the symptoms that may accompany lightheadedness, common causes, when to see a healthcare provider, tests, and treatment.

Symptoms of Lightheadedness

Most of the time, lightheadedness is an isolated symptom that goes away on its own. However, it may sometimes be one of many symptoms, especially when the cause is due to an underlying medical condition like an inner ear infection, dehydration, heart failure, or a stroke.

Concerning associated symptoms may include:

• Nausea
• Vomiting
• Vertigo (a spinning sensation)
• Loss of balance
• Sweating
• Headache
• Chest pain
• Fatigue
• Confusion
• Blurred or double vision 
• Shortness of breath or difficulty breathing
• A sense of impending doom
• Rapid heartbeat
• Slurred speech

Causes of Lightheadedness

The long list of conditions that cause lightheadedness includes mostly non-life-threatening ones that don't require medical treatment. However, there are some serious conditions that require urgent medical evaluation.

The most common causes of lightheadedness include:

• Hyperventilation (rapid or deep breathing)
• Extreme physical exertion
• Breathing at high altitude
• Motion sickness
• Dehydration (losing more fluids than you replace)
• Electrolyte imbalance (lower or higher levels of charged particles, such as sodium, potassium, or calcium, in your blood)
• Vertigo (primarily due to inner ear infection)
• A side effect of medication
• Panic attack
• Low blood sugar
• Orthostatic hypotension (a drop in blood pressure due to standing or sitting too quickly)
• Heart attack (blockage of blood flow to the heart muscle)
• Stroke (blockage of blood flow or bleeding in the brain)
• Overheating (heat intolerance)
• Diabetes 
• Anemia (low number of healthy red blood cells)
• Pregnancy

What Medications Can Cause Lightheadedness

If you suspect that your medication is causing you to be lightheaded, consult with a healthcare provider, regardless of whether or not lightheadedness is a stated side effect.

Sometimes a regular medication you take can interact adversely with an over-the-counter (OTC) medication or a particular food you ate, causing lightheadedness.

Other times, medication may lower your blood sugar or blood pressure to an unhealthy level, causing you to feel faint. A healthcare provider can provide guidance on whether you should lower the dose or discontinue the medication. Never discontinue a medication without speaking to your healthcare provider first.

There is a long list of drugs that come with the side effects of lightheadedness. The following list is not complete, but it includes the most common drugs classes associated with lightheadedness (Note: some of these drugs have also been associated with vertigo or dizziness, but these symptoms are not the same as lightheadedness):

• Diuretics (water pills): Thiazides including Diuril (chlorothiazide), Hygroton (chlorthalidone), and Microzide (hydrochlorothiazide), loop diuretics including Bumex (bumetanide) and Lasix (furosemide), and potassium-sparing agents including Midamor (amiloride) and Aldactone (spironolactone)
• High blood pressure medications, such as alpha-blockers
• Some antidepressants, such as tricyclic antidepressants and monoamine oxidase inhibitors (MAOIs)
• Some anti-seizure drugs, such as Neurontin (gabapentin) and Depakote (valproate)

How to Treat Lightheadedness

Most cases of lightheadedness do not require medical treatment, but some home remedies may help alleviate your symptoms or prevent future episodes, including:

• Standing up slowly
• Making sure you have adequate fluid intake, especially on a hot day
• Finding shade or staying in an air-conditioned room during a hot day
• Limiting salt intake
• Getting at least seven hours of sleep 
• Avoiding stress and triggers of anxiety
• Managing your blood sugars, especially if you have diabetes
• Quitting smoking and drinking alcohol

If you have recurrent bouts of lightheadedness or your lightheadedness does not go away with water intake or sitting/lying down after a few hours, you may want to consult a healthcare provider who can evaluate the root cause of your lightheadedness.

Finding and treating the underlying condition causing your lightheadedness is the most definitive way to resolve it. In some cases, medication (such as an antihistamine, anti-nausea, or anticholinergic drug), and even psychotherapy, may be useful tools to help alleviate your persistent symptoms.

Risk Factors Associated With Lightheadedness 

Older age, obesity, diabetes, and high blood pressure are independent risk factors for heart disease and, therefore, put you at higher risk of becoming lightheaded.

In rare cases, recurrent panic attacks, anxiety disorders, and hyperventilation syndrome can cause you to take in less oxygen and exhale more carbon dioxide, throwing off the pH of your blood. This may also increase your risk of feeling faint or lightheaded.

Are There Tests to Diagnose the Cause of Lightheadedness

Taking a detailed medical history and performing a physical examination are the first steps in evaluating the cause of your lightheadedness. Your healthcare provider may ask about your fluid intake, the color of your urine (dark urine may indicate dehydration), food intake, and activity level.

Changes in your body chemistry, such as low blood sugar, potassium, or salt, can cause you to feel off.

Sometimes tests are done to help your healthcare provider narrow down or diagnose the cause of your lightheadedness. These tests may include the following:

• Blood tests: A complete blood count (CBC) and chem 7 (basic metabolic panel) to measure electrolytes and blood glucose are among the initial blood tests that may be performed to determine if low blood sugar, anemia, or electrolyte abnormalities are causing your lightheadedness. 
• Electrocardiogram (EKG): An EKG is a quick, highly accessible, and non-invasive test that can help screen and detect heart abnormalities such as arrhythmias, a more serious cause of lightheadedness.
• Echocardiogram: An echocardiogram is a non-invasive ultrasound test that looks at your heart's ability to pump blood efficiently throughout the body. It can also detect valvular or heart wall abnormalities that can lead to heart failure.
• Computed tomography (CT scan of the head): If your lightheadedness is associated with severe headache, paralysis on one side of the body, or slurred speech, your lightheadedness may be related to a stroke or mini-stroke (transient ischemic attack). A non-contrast CT is a quick way to detect if this is evidence of a blood clot or blood in the brain that may be causing your symptoms.

When to See a Healthcare Provider

See a healthcare provider if you have persistent or recurring bouts of lightheadedness. If you experience the following associated symptoms, consult a healthcare provider or get emergency medical care. The presence of these signs may indicate the presence of a heart attack or stroke requiring immediate medical attention:

• Chest pain
• Difficulty forming words or slurred speech
• Nausea or vomiting 
• Numbness or paralysis on one side of the body
• Blurred or loss of vision
• Trouble breathing
• Severe, sudden headache

Summary

Lightheadedness, or feeling faint, is a common medical complaint affecting people of all ages. Most causes are non-life threatening and resolve relatively quickly without treatment, but some may indicate a more serious underlying condition.

Some common causes include dehydration, physical exertion, orthostatic hypotension, low blood sugar, and side effects of medications. Lightheadedness can also signify diabetes, anemia, or heart conditions. See a healthcare provider if you have concerning symptoms or if lightheadedness persists or recurs.

A Word From Verywell

As you age, you become more prone to lightheadedness due to natural changes in the body. To prevent lightheadedness, stay hydrated, find some shade, eat and drink regularly, be mindful of medication side effects, and try to take it easy when possible to avoid falling and injuring yourself.