Smashing Pumpkins’ Billy Corgan faints onstage.

Smashing Pumpkins frontman Billy Corgan passed out briefly during a concert Wednesday night at a live concert in Tampa Bay, FL. Corgan, 43, Tweeted about the experience, saying: “I have no memory of falling against the drum riser and my guitar cabinet, but I can tell you I’ve got quite a good bruise + am moving slow And for those that saw me fall last night during Bullet, that wasn’t a stage move or clumsiness, that was me blacking out and wiping out.” The episode did not stop the concert, nor is it expected to cause any cancellation of tour dates.

Fainting, medically known as syncope, is a temporary loss of consciousness. It is very common, with about one third of people having suffered at least one episode in their lifetime, and is more common in older people Syncope is caused by a sudden drop in blood flow to the brain. It may be caused by an irregular heart rate or rhythm or by changes of blood volume or distribution. Syncope can occur in otherwise healthy people. The patient feels faint, dizzy, or lightheaded (presyncope), and then may lose consciousness (syncope). Fainting usually lasts only a short time- on the order of seconds to a few minutes.

The causes of syncope can be divided into several different categories:

1. Vasovagal syncope: This is the most common cause of fainting. The vagus nerve is one of the most important nerves in the body, wandering from the brain stem through organs in the neck, chest and abdomen. It is responsible for controlling heart rate, sweating, muscle movements in the mouth (including speech and keeping the larynx open for breathing), and gastrointestinal mobility. Vasovagal syncope is caused by an abnormal circulatory reflex. Although the heart pumps more forcefully and the blood vessels relax, the heart rate does not increase enough to maintain enough blood flow to the brain .” Causes of vasovagal syncope include the following:

• Environmental factors - Especially hot, crowded settings
• Emotional factors - Stress or the sight of blood or threat of injury
• Physical factors - Standing too long with locked knees (especially seen in military personnel)
• Illness - Fatigue, hypoglycemia (low blood sugar), dehydration, or other current illness.

2. Situational syncope: Susceptible people have episodes of syncope only in particular situations. Causes of situational syncope include:

• Cough syncope occurs in people with lung disease when coughing forcefully.
• Swallow syncope occurs upon swallowing in some people with disease in the throat or esophagus.
• Micturition syncope occurs when a susceptible person empties an overfilled bladder, especially in males who are intoxicated with alcohol.
• Carotid sinus hypersensitivity occurs in some elderly people when turning the neck, shaving, or wearing a tight collar.
• Postprandial fainting can occur in elderly people when their blood pressure falls about an hour after eating.

3. Postural syncope: This occurs when a person lying down faints when standing up. Standing up causes a drop in blood pressure, and decreases the amount of blood flowing to the brain. People who have recently started or changed certain cardiovascular medications can be prone to postural syncope. Low blood volume, such as from blood loss, dehydration or heat exhaustion can also increase the risk of postural syncope.

4. Cardiac syncope: The heart can cause syncope by a variety of mechanisms. Cardiac syncope is more concerning than other causes, as its underlying causes can be life-threatening. These mechanisms include:

• Arrhythmia- an abnormal heart rhythm, which can drop blood flow from the heart, either by slowing the heart, or by increasing it so fast that the heart can’t pump effectively.
• Cardiac obstruction- Blockage of blood flow from heart attack, abnormal heart valves, poor heart muscle contraction or other heart conditions.
• Congestive heart failure.

5. Neurologic syncope: Neurologic problems cause fainting (or loss of consciousness) by various mechanisms:

• Seizures are a cause of unconsciousness but are different from fainting. With seizures, the blood flow to the brain does not decrease. Unconsciousness results from disordered electrical discharges within the brain.
• Stroke (bleeding in the brain) can cause syncope associated with headache.
• Transient ischemic attack (TIA or mini-stroke) can cause fainting, usually preceded by double vision, loss of balance, slurred speech, or vertigo (a spinning sensation).

6. Psychogenic syncope: Hyperventilation from an anxiety disorder can cause fainting.