Near-Fainting with Uncertain Cause

Fainting (syncope) is a temporary loss of consciousness (passing out). It happens when blood flow to the brain is reduced. Near-fainting (near-syncope) is like fainting, but you don't fully pass out. Instead, you feel like you are going to pass out, but don't actually lose consciousness.

Signs and symptoms

These are symptoms of near-fainting or symptoms that can be associated with near-fainting:

• Feeling lightheaded or like you are going to faint

• Weak pulse

• Nausea

• Sweating

• Blurred vision or feeling like your vision is fading

• Palpitations

• Chest pain

• Trouble breathing

• Feeling cool and clammy

Causes

Fainting typically happens when your blood pressure suddenly drops, and not enough blood flows to your brain.

Common minor causes include:

• Sudden emotional stress such as fear, pain, panic, or the sight of blood

• Straining or overexertion, such as straining while using the toilet, vomiting, coughing, or sneezing

• Standing up too quickly, or standing up for too long a time

More serious causes include:

• Very slow, fast, or irregular heart rate (arrhythmia)

• Dehydration

• Significant blood loss

• Medicines, or a recent change in medicines. Medicines that can cause fainting include blood pressure or heart medicines.

• Heart attack

• Heart valve problems

Remember, even minor causes can become serious if you fall and injure yourself, or are driving. You may need more tests. It's very important that you follow up with your doctor as advised.

Home care

These guidelines will help you care for yourself at home:

• Rest today. Resume your normal activities as soon as you are feeling back to normal.

• If you become lightheaded or dizzy, lie down right away or sit with your head between your knees.

• Drink plenty of fluids and don't skip meals.

Because the exact cause of your near fainting spell is not known, another spell could occur without warning. To stay safe, don't drive a car or use dangerous equipment. Don't take a bath alone. Don't swim alone. You can resume these activities when your healthcare provider says that you are no longer in danger of having a near-fainting spell.

Follow-up care

Follow up with your healthcare provider, or as advised.

Call 911

Call 911 or seek emergent care if any of the following occur:

• Another near-fainting or full fainting spell occurs, and it's not explained by the common causes listed above

• Chest, arm, neck, jaw, back or abdominal pain

• Shortness of breath

• Weakness, tingling, or numbness in one side of the face, or in one arm or leg

• Slurred speech, confusion, trouble walking or seeing

• Seizure

When to seek medical advice

Call your healthcare provider for advice if any of these occur:

• Changes in your medicines

• You start to have near fainting on a more frequent basis

Note about concussion

If you had an injury to the head, it is possible that you could have a concussion (mild brain injury). Symptoms of a concussion can show up later. For this reason, be alert for symptoms of concussion once you’re home. 
Seek emergency medical care if you have any of the symptoms below over the next hours to days:

• Headache
• Nausea or vomiting
• Dizziness
• Sensitivity to light or noise
• Unusual sleepiness or grogginess
• Trouble falling asleep
• Personality changes
• Vision changes
• Memory loss
• Confusion
• Trouble walking or clumsiness
• Loss of consciousness (even for a short time)
• Inability to be awakened

During the time period that you’re watching for concussion symptoms:

• Don’t drink alcohol or use sedatives or medicines that make you sleepy.
• Don’t drive or operate machinery.
• Don’t do anything strenuous, such as heavy lifting or straining.
• Limit tasks that require concentration. This includes reading, watching TV, using a smartphone or computer, and playing video games.
• Don’t return to sports, exercise, or other activity that could result in another injury.

Ask your healthcare provider when you can safely resume these activities.