What Are the Most Common Causes of Syncope?

Syncope is a disturbance of consciousness caused by transient insufficiency of cerebral blood supply for various reasons.

Basic Information

English name

fainting

Visiting department

Neurology

Common causes

Autonomic neuromodulation disorders, vasomotor disorders, cardiogenic cerebral ischemia, sudden inadequate blood supply to the brainstem, etc.

Common symptoms

Suddenly feel dizzy, dizzy, blurred vision or dark eyes, weak limbs, loss of consciousness

Causes of syncope

Cerebral perfusion pressure depends on the arterial pressure of the systemic circulation, so any cause of decreased cardiac output or decreased peripheral vascular resistance can cause syncope. Common reasons are:

1. Autonomic dysregulation, vasomotor disorders

Such as hypotension in the upright position can cause syncope, and poor physical fitness is more common; a large number of one-time urination or continuous cough, can reduce the amount of returning blood to cause syncope.

2. Cardiogenic cerebral ischemia

Syncope of this cause is the most severe and is more common in severe rapid or slow arrhythmias and cardiac arrest. It can occur in any position, and severe ischemia can be accompanied by limb twitching and incontinence.

3. Cerebrovascular disease

This situation is mostly caused by sudden insufficient blood supply to the brain stem. The brain reticular structure is unable to maintain a normal state of consciousness due to the ischemia of the ascending activation system.

4. Other

Syncope is also seen in hypoglycemia, severe anemia, and hyperventilation.

Clinical manifestations of syncope

The patient suddenly felt dizzy, stunned, blurred vision or blackened eyes and weak limbs. This is a sign of syncope. With the loss of consciousness, he fell to the ground and recovered as usual within seconds to minutes. Patients can feel general weakness within half an hour. In many cases, patients fall quickly rather than fall, have no loss of consciousness, or have recurrence and experience. If they squat in time, the symptoms will soon disappear. Heart rate slows down or increases during syncope, blood pressure drops, the complexion becomes pale, and cold sweats can occur. Syncope basically occurs in a standing or sitting position. If it occurs in the supine position, you should pay attention to whether you have cardio-cerebral vascular disease such as arrhythmia, transient ischemic attack or epilepsy.

Differential diagnosis of syncope

Should be distinguished from vertigo. Syncope and dizziness are completely different symptoms. Loss of consciousness when syncope occurs. When vertigo occurs, no matter how severe and how long it lasts, there should be no conscious disturbance.

Syncope treatment

First aid treatment: No matter what causes syncope, put the patient in a supine position immediately, take the head and feet down, loosen the belt, and keep warm. Witnesses can also start with a centripetal massage from the lower extremities to promote blood flow to the brain; at the same time, they can press the patient's Hegu or Renzhong points to awaken the patient through painful stimulation; do not rush to get up after awake to avoid causing syncope again; If you consider that the patient has an organic disease, after the on-site treatment, such as hypoglycemia patients give sugar supplements, cough syncope to cough, etc., you must go to the hospital in time to treat the cause of syncope.