Presyncope, or feeling like you are going to faint, can be caused by strong emotions, panic attacks, sudden changes in position, prolonged exposure to the heat, anemia, hypoglycemia, heart attack, or stroke.
Presyncope is typically accompanied by symptoms like dizziness, pallor, or cold sweats, and resolves within minutes without causing someone to actually faint or lose consciousness.
If this feeling does not pass, however, it typically results in fainting, which requires immediate medical attention to determine the cause and arrange for appropriate treatment.
Common causes
The main causes of presyncope are:
1. Strong emotions
Strong emotions like stress, fear, pain, or anxiety can cause presyncope.
This is because these emotions can provoke an involuntary reflex in the body that stimulates the vagus nerve, resulting in a drop in blood pressure and heart rate that briefly reduces blood flow to the brain.
What to do: it is important to find ways to relax in order to reduce stress and anxiety. In these cases, talk therapy can be useful to help learn how to handle these emotions.
Read more about stress vs anxiety.
2. Panic attacks
Panic attacks are a symptom of panic or anxiety disorders, which can cause both physical symptoms and intense emotions.
The main symptoms of a panic attack are feelings of fear, shortness of breath, chest tightness, rapid heart beat, tremors, intense sweating, anxiety, and a feeling like you are going to faint.
These symptoms are usually recurrent, coming on suddenly and increasing in intensity over the course of a few minutes and improving within 5 to 20 minutes.
What to do: get yourself to a safe place and breathe deeply, inhaling through the nose and exhaling slowly through the mouth, trying to remain calm and remembering that the episode will pass in a few minutes.
In addition, it is important to make an appointment with a psychologist or other mental health professional. Medications like antidepressants or anxiolytics (anxiety medication) may be indicated in some cases and can be prescribed by a psychiatrist.
3. Sudden changes in position
Sudden position changes, such as standing up too fast, can cause a rapid drop in blood pressure and result in symptoms of presyncope.
This sudden drop in blood pressure, also known as orthostatic hypotension, can be accompanied by other symptoms such as blurry vision, confusion, or dizziness.
What to do: make sure to stand up slowly from a sitting or lying down position in order to prevent a sudden drop in blood pressure. This is especially important for older adults, as sudden drops in blood pressure can increase the risk for falls and bone fractures.
4. Prolonged standing
Standing for long periods of time can result in blood pooling in the legs, making it difficult to pump the blood back up to the heart and reducing blood flow to the brain, causing a person to feel faint and like they are going to pass out.
Prolonged standing can also cause swelling in the legs, feet, and ankles.
What to do: try to avoid spending many hours on your feet. If this is not possible, make sure to flex the knees and ankles every hour or elevate your heels off the floor to help pump the blood from the legs back up to the heart, thus lowering the risk for presyncope.
5. Hypoglycemia
Hypoglycemia is a sharp drop in blood sugar resulting in symptoms like dizziness, shaking, cold sweats, pale skin, palpitations, confusion, or feeling like you are going to faint.
Hypoglycemia occurs most commonly in people with diabetes who are being treated with insulin or other diabetes medications, however it can also be caused by going a long time between meals, drinking alcohol, or from intense physical exercise.
What to do: eating small meals every 2 to 3 hours can help prevent hypoglycemia. If symptoms of hypoglycemia arise, it is important to consume fast-acting carbohydrates like orange juice or candy to rapidly increase your blood sugar.
People with diabetes should also have regular follow up with their primary care provider and/or endocrinologist for blood tests to measure glucose levels and adjust the doses of their medications if necessary.
6. Prolonged heat exposure
Prolonged exposure to the heat can cause an abnormal increase in body temperature known as hyperthermia, which can result in dizziness and presyncope.
In addition to presyncope, other symptoms like excessive sweating, vertigo, nausea, confusion, or even seizures can occur.
Prolonged heat exposure can happen in areas with high temperatures or from exercising, working, or wearing too much clothing in very hot or humid climates.
What to do: get yourself into the shade or to a cooler area; drink lots of cold water, electrolyte beverages, or homemade rehydration solutions to keep the body hydrated; and remove excess clothing, tight clothing, or heavy layers. If symptoms do not improve, head to the nearest emergency room right away for treatment with IV fluids and total body cooling.
7. Heart attack
A heart attack (or myocardial infarction) is an abrupt interruption in blood flow to the heart that can result in cardiac cell death in the affected region. Symptoms include chest pain that may radiate to one or both arms (usually the left), the shoulder, the neck, the jaw, the armpit, or the back.
Pain in the chest, shoulder, and arm may be accompanied by other symptoms like dizziness, malaise, nausea, cold sweats, pallor, presyncope, or syncope.
Read more about symptoms of a heart attack.
What to do: seek emergency medical attention by calling 911 or going to the nearest emergency room if you are experiencing any symptoms of a heart attack (do not drive yourself). A heart attack is a serious, life-threatening condition requiring immediate treatment.
Treatment of a heart attack may involve medication as well as procedures like a cardiac catheterization or angioplasty to restore blood flow to the heart and prevent complications.
8. Cardiac arrhythmias
Cardiac arrhythmias are an alteration in normal heart rhythm, causing the heart to beat faster or slower. Symptoms include dizziness, presyncope, weakness, chest pain, shortness of breath, and general malaise.
Cardiac arrhythmias can be caused by a heart attack, high blood pressure, diabetes, heart valve disease, thyroid problems, sleep apnea, or even the use of certain medications.
What to do: seek immediate medical attention in the emergency department for any arrhythmia symptoms. This is to ensure the cause of the arrhythmia is identified and the appropriate treatment can be started as soon as possible.
9. Stroke
A cerebrovascular accident (CVA), or stroke, as well as other neurological conditions like Parkinson's disease, a brain tumor, or Alzheimer's disease, can cause dizziness, loss of balance, and presyncope.
Other stroke symptoms include weakness on one side of the body, slow or garbled speech, and facial drooping or twisting.
What to do: call 911 or get to the nearest emergency department right away if you are experiencing any symptoms of a stroke (do not drive yourself). A stroke is a medical emergency that requires immediate treatment. Like other neurological disorders, a stroke is treated by a neurologist through the use of specific medications.
10. Iron deficiency anemia
As the name implies, iron deficiency anemia is caused by a lack of iron in the body. Iron is important for the production of hemoglobin and the formation of red blood cells, which are the cells that transport oxygen to the tissues.
A lack of oxygen, especially to the brain, can result in symptoms like presyncope, dizziness, sleepiness, excessive fatigue, pallor, or shortness of breath.
What to do: iron deficiency anemia is treated by a primary care provider or hematologist and normally involves the use of iron supplements in addition to eating foods high in iron, such as lentils, parsley, beans, and red meat.
11. Labyrinthitis
Labyrinthitis is an inflammation of the labyrinth, which is a structure located in the inner ear that is responsible for hearing and balance. Labyrinthitis symptoms include dizziness, vertigo, loss of balance, hearing loss, nausea, and presyncope.
Labyrinthitis is more common in older adults, but it can happen at any age. Causes include respiratory infections, diabetes, high blood pressure and even emotional factors like stress, anxiety, or depression.
What to do: consult an otolaryngologist (ENT) for the best treatment, which may involve antiemetics and/or medications to treat vertigo as well as antibiotics if a bacterial infection is present. It is also recommended to avoid stress, caffeine, sugar, and cigarettes, which can worsen symptoms.
12. Medication side effects
Some medications, such as antihypertensives and diuretics, can cause a marked drop in blood pressure resulting in presyncope.
This side effect is more common with very high doses of these medications.
What to do: it is important to consult your primary care provider or prescribing provider to assess for side effects and, if necessary, alter your dose or switch your medication. Never change the dose or stop taking your medication on your own without first consulting your doctor or healthcare team.
Prevention tips
If you are experiencing symptoms of presyncope, lie down immediately with your legs elevated above the level of your heart to improve blood flow to the brian and avoid fainting.
If it is not possible to lie down, sit down and put your head between your knees.
It is important to remain in these positions until the feeling passes.
When to see a doctor
Presyncope typically occurs suddenly and goes away on its own within a few minutes.
However, it is important to be seen immediately at the closest emergency department in the following situations:
- Presyncope that does not resolve, happens frequently, or results in fainting;
- Chest pain that radiates to your arm, neck, jaw, or back;
- Nausea or vomiting;
- Loss of balance;
- Weakness on one side of the body or difficulty speaking;
- Cold sweats, pallor, tremors, or weakness;
- Heart palpitations or shortness of breath;
- Somnolence (sleepiness) or confusion.
People with a history of diabetes, epilepsy (seizures), or heart problems who experience presyncope should always be seen at the hospital.
A doctor or other healthcare provider will evaluate your symptoms, take a detailed medical history, and order tests to determine the cause of the presyncope and arrange for the most appropriate treatment.