Syncope: 15 Possible Causes (by Age Group) & What to Do

Dr. Clarisse Bezerra
Medical review: Dr. Clarisse Bezerra Family Doctor CRM 16976-CE / OMP 69634
Created by: Tua Saude editing team

Syncope, commonly known as fainting, refers to a temporary loss of consciousness that often results in a fall. Before it happens, symptoms like paleness, dizziness, sweating, blurred vision, and weakness may occur. Several factors can trigger syncope, including low blood pressure, low blood sugar, and extreme heat. In some cases, it can also be caused by heart or nervous system problems. If you feel faint, it's important to sit down or lie down immediately.

Fainting can happen to anyone, even without a diagnosed health condition. It's a sign that your brain isn't receiving enough blood. If you experience syncope, you should seek medical advice to determine the underlying cause. A healthcare provider will evaluate your symptoms and may perform tests, such as blood tests or imaging, to find the root cause and recommend appropriate treatment.

Because syncope can be a symptom of more serious conditions, such as heart disease or neurological disorders, it’s important to understand the causes, symptoms, and prevention strategies. Knowing when to seek medical attention can help prevent complications from fainting.

Woman with hand on head

Common causes

Anyone can experience syncope, even without any underlying medical conditions.

Some of the most common causes include:

  1. Low blood pressure: Often occurs when standing up too quickly, leading to dizziness, headache, imbalance, and fatigue

  2. Prolonged fasting or going without food for more than 4 hours: This can result in hypoglycemia (low blood sugar), causing symptoms like shaking, weakness, cold sweats, and confusion

  3. Seizures: These may occur due to epilepsy or head trauma, leading to shaking, excessive salivation, teeth clenching, and in some cases, involuntary urination and defecation

  4. Excessive alcohol or drug use: These can lead to a drop in blood pressure, causing fainting

  5. Medications: Certain medications, particularly those used for blood pressure or diabetes, can cause syncope when taken in high doses

  6. Extreme heat: Exposure to very hot conditions, such as being on the beach or in a hot bath

  7. Extreme cold: Such as being exposed to snow

  8. Intense physical exertion: Long periods of vigorous physical activity can lead to fainting

  9. Anemia, dehydration, or severe diarrhea: These can disrupt the body's balance of nutrients and minerals, leading to fainting

  10. Anxiety or panic attacks: These emotional responses can lead to fainting in some individuals

  11. Severe pain: Intense pain can cause a drop in blood pressure, leading to fainting

  12. Head injury: A fall or trauma to the head can lead to fainting

  13. Migraine headaches: These are often accompanied by severe pain, neck pressure, and ringing in the ears

  14. Standing for long periods: Especially in hot, crowded environments

  15. Fear: Emotional responses such as fear of needles or animals can trigger syncope

Since syncope is often caused by reduced blood flow to the brain, it can be a sign of serious underlying issues, such as brain conditions or heart problems, like arrhythmias or aortic stenosis.

Causes by Age Group

The causes of syncope can vary by age group. Here is a breakdown of the most common causes by age group:

Age Group Common Causes
Elderly Low blood pressure upon waking, high doses of antihypertensive or hypoglycemic medications, cardiac problems like arrhythmias or aortic stenosis
Children and Adolescents Prolonged fasting, dehydration, or diarrhea
Pregnant Women Low blood pressure, prolonged periods of lying on the back or standing

However, any cause of syncope can occur at any age or stage of life.

What to do if you feel faint

If you feel faint and experience symptoms such as dizziness, weakness, or blurred vision, you should lie down and raise your legs above the level of your body, or sit and bend forward toward your legs.

It’s important to avoid stressful situations and to avoid standing for long periods in the same position.

How to prevent fainting

To help prevent fainting, follow these recommendations:

  • Drink plenty of fluids throughout the day and eat every 3 hours

  • Avoid exposure to extreme heat, especially during summer

  • Get up slowly from bed, sitting first before standing

  • Be aware of situations that commonly trigger fainting, such as blood draws or injections, and inform your nurse or pharmacist

It’s important to prevent fainting whenever possible, as it can lead to injuries, including fractures, due to the sudden loss of consciousness.

When to see a doctor

After experiencing syncope, it’s important to consult a doctor to determine the cause. In some cases, you should seek emergency medical attention immediately:

  • If you have an underlying condition like diabetes, epilepsy, or heart problems

  • After physical exercise

  • Following a head injury

  • If the fainting episode lasts more than 3 minutes

  • If you experience other symptoms like intense pain, vomiting, or drowsiness

  • If fainting occurs frequently

  • If you experience excessive vomiting or severe diarrhea

In these cases, the patient needs to be evaluated by a doctor to assess their health and, if necessary, undergo additional tests such as blood tests or a CT scan.

Update History
We regularly update our content with the latest scientific information to maintain an exceptional level of quality.
  • 5 November, 2025 (Current version)
    Updated by Daisy Oliveira - Registered Nurse
  • 3 November, 2025
  • Created on November, 2025

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