Fainting

Fainting refers to an episode of loss of consciousness which usually lasts for a few seconds to a few minutes. Fainting is a neurological emergency as it can be caused by heart disorders (especially abnormal heart rhythm and heart attack) and Seizures, which can be life-threatening. As such, all patients who have fainting must immediately consult the Neurologist.

What are the causes of fainting?

a. Brain disorders

The most likely possibility is Seizure, which is caused by abnormal brain cell activity. Seizure is characterized by jerky movement of limbs, up rolling of eyeballs, tongue biting, and urine incontinence (loss of ability to control the urination resulting in wetting the pants). Seizure is life-threatening because it can cause difficulty in breathing and the heart to stop beating.

Even though the cause of Seizure is mostly unknown, it can be due to brain cancer, Stroke, and Meningoencephalitis (Infection of the brain), which are all life-threatening conditions.

b. Heart disorders

Abnormal heart rhythm results in ineffective pumping of blood to the brain, depriving the brain cells of oxygen, and leading to dizziness. In severe cases, patients have a loss of consciousness and fainting attacks. Occasionally heart attack can present as fainting.

c. Low blood pressure

When patients have low blood pressure, there is a reduction in blood flow to the brain, leading to an inadequate amount of oxygen in the brain. Consequently, patients have dizziness and fainting attacks.

The underlying causes of low blood pressure are as follows:

• Dehydration – insufficient amount of water in the body due to vomiting and diarrhea
• Excessive doses of high blood pressure medications
• Neurological disorders such as Parkinson’s disease, can cause drop in blood pressure.
• Hormonal deficiency.

d. Blood disorders

Fainting can be caused by Anemia (inadequate amount of blood in the body) and low or high glucose levels.

e. Emotional disorders

These refer to Anxiety (excessive worrying and thinking), Depression (feeling low or sad), and work-related stress. Emotional disorders can cause a reduction of blood flow to the brain, resulting in fainting.

What will the Neurologist do for patients with fainting?

The Neurologist will perform a physical examination, blood tests, CT / MRI brain scan, heart scan (Echocardiogram), Holter study (recording of heart rhythm), and other relevant tests.  Some patients may need to be referred to the Cardiologist (heart specialist).

For patients with Seizure, the neurologist will immediately administer intravenous medication to stop the Seizure.

Dr Chew Nee Kong
Consultant Neurologist.

   Back