Nausea and Lightheadedness: Causes and Treatments

It's not unusual to occasionally experience nausea or lightheadedness; both are common and usually have nonserious causes. Sometimes these symptoms can occur together, as in the case of endurance athletes (like marathon runners) who overexert themselves.

However, nausea and lightheadedness together may be signs of something more serious, particularly if they occur for no apparent reason or are accompanied by other symptoms such as irregular heartbeat or rash.

This article explores the symptoms and causes of nausea and lightheadedness, including how they can be treated and prevented. It also explains when nausea and lightheadedness are signs of a medical emergency needing immediate care.

Person sitting on floor at home feeling lightheadedness and nausea

FG Trade / Getty Images

Symptoms of Nausea and Lightheadedness

Nausea is a nonspecific symptom characterized by the following features:

  • A loss of appetite
  • A feeling that you are about to vomit
  • A general queasiness in your stomach, chest, and back of the throat

Nausea may also be accompanied by profuse sweating; a "gurgling" stomach; and rhythmic contractions of the stomach, chest, and throat (retching). Nausea may precede vomiting or occur on its own.

Lightheadedness is another term for presyncope, meaning the sensations you have before fainting (syncope). Symptoms of presyncope can vary but may include:

  • Dizziness
  • Blurred vision, tunnel vision, or a visual "whiting out"
  • The marked dulling of sounds
  • Sudden disorientation
  • A spontaneous outbreak of sweat
  • A feeling that you are about to faint

What Causes Nausea and Lightheadedness?

Many conditions can cause nausea and lightheadedness. Most are not serious, but others are potentially life-threatening.

Hypoglycemia

Hypoglycemia is the medical term for low blood sugar (glucose). Glucose is the body's main energy source. When levels fall too low, the body is less able to function normally.

Symptoms of hypoglycemia tend to develop when glucose levels are below 70 milligrams per deciliter of blood (mg/dL).

At this level, hypoglycemia can cause neuroglycopenic symptoms (such as lightheadedness, fatigue, and blurred vision) due to the depletion of glucose in the brain. At the same time, adrenergic symptoms (such as nausea, rapid heart rate, and sweating) can occur due to associated imbalances in adrenaline levels.

Hypoglycemia is common among people with uncontrolled diabetes. It can also occur in those without diabetes due to excessive alcohol use, severe infections, certain medications, or hormonal disorders like Addison's disease.

Migraine

Migraine is a common neurological (brain-related) disorder that causes recurrent headaches, sometimes severe. The headaches are often described as throbbing or pounding and usually affect one side of the head. Nausea is common, which can precede or accompany a migraine attack.

If lightheadedness occurs, it is likely the result of vestibular migraine, characterized by dizziness, vertigo (spinning sensations), and presyncope. As with all migraines, nausea and vomiting are common with vestibular migraine.

Vertigo Attacks

Vestibular migraine is the most common cause of vertigo attacks and accounts for roughly 9% of all visits to migraine clinics.

Vasovagal Syncope

Vasovagal syncope is when a sudden drop in blood pressure (called hypotension) causes you to faint. It is a common and often unexplained event typically preceded by a sudden wave of nausea, lightheadedness, flushing, sweating, and blurred vision. In some cases, you may experience these prodromal (preceding) symptoms but not fainting.

Vasovagal syncope occurs when the part of the nervous system that regulates heart rate and blood pressure suddenly malfunctions. This causes the heart rate to slow and blood vessels to dilate (widen), leading to a steep drop in blood pressure.

The cause of vasovagal episodes is not always clear, although it is thought to be an exaggerated reaction to a triggering event, such as:

  • Intense pain
  • Intense fear
  • Fasting
  • Dehydration
  • Seeing blood or having blood drawn
  • Standing for a long time
  • Being in a crowded or overheated environment
  • Straining (such as having a bowel movement)

Prevalence

Studies suggest that one-third of all people have at least one vasovagal syncope spell sometime in their lifetime.

Epilepsy

Unexplained episodes of nausea and lightheadedness may be signs of certain types of epilepsy, a brain-related disorder that causes seizures.

People who experience focal seizures, also known as auras, will not lose consciousness but may experience sensory symptoms such as nausea and odd smells. A sudden drop in blood pressure and heart rhythm changes may also occur and lead to lightheadedness and dizziness.

A focal seizure may occur on its own or lead to a classic generalized seizure.

Anxiety Attacks

Anxiety attacks, also known as panic attacks, are intense and sudden feelings of fear or doom that manifest with physical symptoms. In panic disorder, these attacks arise in the absence of a threat or when the threat is disproportionately smaller than the response.

Common symptoms of anxiety attacks include:

In extreme cases, the reaction can be severe enough to cause lightheadedness, dizziness, and fainting.

Medications

Any number of medications can cause nausea. Some also directly or indirectly affect blood pressure, triggering presyncope.

Some of the medications that can cause nausea and lightheadedness include:

Carbon Monoxide Poisoning

Carbon monoxide poisoning is characterized by lightheadedness and nausea. It occurs when a colorless, odorless, tasteless gas called carbon monoxide builds up in your bloodstream.

Carbon monoxide is produced by burning gasoline, wood, propane, charcoal, or other fuel. When you breathe in too much (usually while you are in a tightly enclosed space with poor ventilation), your body will replace the oxygen in your red blood cells with carbon monoxide, exposing cells and tissues to its toxic effects.

Other symptoms include blurred vision, shortness of breath, confusion, and vomiting. If not removed from the source of the toxic fume, a person can pass out and die.

Heart Attack

A heart attack, also known as myocardial infarction, occurs when an artery that sends blood and oxygen to the heart muscle is blocked.

The six classic symptoms of a heart attack are:

  • Chest pain (angina)
  • Shortness of breath
  • Pain, stiffness, or numbness in one or both arms, the back, shoulders, neck, jaw, or upper abdomen
  • Cold sweat
  • Nausea or vomiting
  • Lightheadedness, dizziness, or fainting

Not all heart attacks are readily recognizable. In some cases, you may only experience signs like nausea and lightheadedness. These are referred to as silent heart attacks.

Silent Heart Attacks

According to the American Heart Association, roughly 1 in 7 heart attacks in the United States are "silent," meaning that they lack obvious symptoms. As a result of delayed treatment, a person with a silent heart attack is 35% more likely to experience heart failure (the heart does not pump enough blood for the body's needs).

Brain Tumors

A less likely cause of nausea and lightheadedness is a brain tumor. These include malignant (cancerous) tumors and benign (noncancerous) ones. Both produce symptoms that vary based on the tumor's size, type, and location. A headache is the most common sign.

Tumors that develop in parts of the brain known as the brain stem and basal ganglia can cause nausea and lightheadedness by impairing functions like blood pressure, respiration, and digestion.

The most common type of brain cancer, glioma, is known to cause bradycardia (slowed heart rate) and presyncope when it occurs in the basal ganglia. Nausea and vomiting are also common.

How to Treat Nausea and Lightheadedness

The treatment of nausea and lightheadedness varies by the cause. You may be able to treat these symptomatically with home remedies, diet, medications, and mind-body therapies.

See a healthcare provider for diagnosis and treatment if you experience these symptoms without an obvious cause, if they are severe, or if they recur.

Nausea Remedies

If you have nausea, some of the treatment options include:

  • Home remedies: Ginger is an age-old cure-all for nausea. Try sipping ginger tea, sucking on ginger candy, or chewing on a tiny sliver of fresh ginger.
  • Diet: A bland diet can help ease stomach queasiness, whether the cause is gastrointestinal or not. You should also avoid greasy, spicy, or smelly foods.
  • Breathing exercises: Balanced breathing (in which you inhale slowly through the nose, hold for several seconds, and exhale slowly through the mouth) has proven effective in relieving nausea, even among people on chemotherapy.
  • Aromatherapy: Peppermint aromatherapy may help ease nausea by inducing calm. It also has a soothing effect on the throat and esophagus that may help ease retching.
  • Over-the-counter (OTC) drugs: OTC antihistamines like Benadryl (diphenhydramine) and Unisom (doxylamine) may help ease nausea. They also induce drowsiness to help you sleep.
  • Prescriptions: Certain prescription antihistamines alleviate nausea symptoms, including Phenergan (promethazine) and Vistaril (hydroxyzine).

Lightheadedness Remedies

If you experience lightheadedness, you can do several things:

  • Sit or lie down: If lying down for a few minutes, sit up slowly and remain sitting for one to two minutes before slowly standing up.
  • Drink plenty of fluids, especially water: This is especially important if you have lost fluid due to excessive diarrhea or vomiting.
  • Know your triggers: If you experience presyncope as a result of anxiety or stress (mental or physical), avoid situations that trigger reactions.
  • Adjust medications: If your symptoms are drug-related, a dose adjustment or drug substitution may be needed.
  • See a heart specialist: If cardiovascular problems, like heart rhythm or heart valve problems, are contributing to frequent lightheadedness, see a specialist known as a cardiologist. Medications and procedures (like pacemaker surgery or heart valve replacement) may be needed.

What About Children?

On its own, nausea is a condition that can usually be managed in children. On the other hand, lightheadedness may be a cause for concern if it is recurrent and/or leads to fainting. Certainly, for parents and caregivers, fainting or near-fainting episodes can be alarming.

In most cases, the cause of presyncope in children will not be serious. Around 1 out of every 6 children will experience a fainting spell at some point by age 18. In most cases, it will happen only once.

However, frequent lightheadedness should not be ignored. On rare occasions, it may be a sign of an undiagnosed heart condition or epilepsy.

How to Prevent Nausea and Lightheadedness

There is often no way to completely avoid nausea and lightheadedness. They can happen after doing something simple as watching an IMAX movie or exerting yourself more than you intended.

However, if you've experienced nausea and lightheadedness either frequently or severely, you can take steps to avoid future episodes, depending on the underlying cause:

  • Hypoglycemia: To avoid a drop in blood sugar, do not skip meals, and keep healthy snacks on hand to tide you over between meals. If you have diabetes, adhere to your recommended treatments and monitor your blood sugar to keep levels under control.
  • Migraine: To help avoid migraine attacks, exercise regularly, keep regular sleep hours, avoid skipping meals, and manage your stress. You can also speak with a healthcare provider about prophylactic (preventive) drugs like Depakote (divalproex sodium) and Topamax (topiramate).
  • Vestibular syncope: Avoid crowded, overheated spaces or any other known triggers for fainting spells. If the sight of blood or needles causes you distress, let the healthcare provider know in advance before getting a blood draw.
  • Epilepsy: If you have epilepsy, you need to take your medications as prescribed. Alcohol is not recommended for people with epilepsy, and neither are recreational drugs. It is also important to sleep regularly, eat regularly, and manage your stress.
  • Anxiety attacks: In addition to identifying and avoiding triggers for panic attacks, speak with a therapist or psychiatrist to pinpoint the root cause of your anxiety. Medications called anxiolytics can be prescribed to help keep anxiety symptoms under control.

When to See a Healthcare Provider

If nausea and lightheadedness are severe, persistent, or occurring without a known cause, please see a healthcare provider for a further workup.

One rare but potentially life-threatening cause of nausea and lightheadedness is anaphylaxis. Anaphylaxis is a severe, whole-body allergy that occurs after exposure to certain drugs, foods, insect stings, and other allergy-causing substances (allergens).

Call 911 if you experience the following signs and symptoms of anaphylaxis after exposure to a known or suspected allergen:

  • Lightheadedness or dizziness
  • Nausea or vomiting
  • Sudden rash or hives
  • Shortness of breath
  • Wheezing
  • Severe stomach pain
  • Rapid or irregular heartbeat
  • Swelling of the face, lips, or threat
  • A feeling of impending doom

If left untreated, anaphylaxis can lead to shock, coma, asphyxiation, acute respiratory failure, cardiac arrest, and death.

Summary

Individually, there are many possible causes of nausea and lightheadedness. When they occur together, it may be due to relatively common conditions like hypoglycemia, migraine, extreme anxiety, and medication side effects. Less common causes include epilepsy, brain tumors, heart attacks, anaphylaxis, and carbon monoxide poisoning.

A Word From Verywell

It can be scary to suddenly experience nausea and lightheadedness and not know why. Fortunately, most cases are not serious and tend to pass without further incident. Even so, it's important to let a healthcare provider know about it at your next appointment.

Based on your medical history, a healthcare provider may advise you to remain watchful and report any future incidents. Or you may be advised to undergo tests or procedures if you are at risk of heart disease, diabetes, or other acute or chronic illnesses.

If nausea and lightheadedness occur repeatedly, schedule an appointment as soon as possible. To aid with the diagnosis, bring information about when and where the episodes occurred.

Frequently Asked Questions

  • Is lightheadedness the same as dizziness?

    Lightheadedness is the feeling that you are about to faint. Dizziness is when you feel unbalanced or feel the room spinning. Dizziness often accompanies lightheadedness.

  • Is vasovagal syncope the same as orthostatic hypotension?

    Not exactly. Vasovagal syncope occurs when you faint because your body overreacts to certain triggers (like the sight of blood). If you feel faint while standing, this is called orthostatic hypotension. The two conditions can co-occur and are sometimes mistaken for the other.

  • What causes presyncope?

    Presyncope, more commonly known as lightheadedness, can be caused by many different things, including:

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Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By James Myhre & Dennis Sifris, MD
Dennis Sifris, MD, is an HIV specialist and Medical Director of LifeSense Disease Management. James Myhre is an American journalist and HIV educator.