Before fainting, you may have sweaty palms, dizziness, lightheadedness, problems seeing, or nausea. In young people, the problem usually has no serious cause, though falls related to fainting can lead to injury. But in some cases, it can be due to an underlying heart problem that is more concerning. Triggers include:. Fainting in an older person, a person with heart disease, or during exertion, or while lying down can be a cause for concern. In any of these cases you should call your healthcare provider.
It's important to diagnose the cause of the fainting. Most people who faint stay out a few seconds to less than a minute. If the person is unconscious for a longer time, call To find out if the cause of your fainting is serious, your healthcare provider will ask you questions about how often you faint, how long they last, and the events surrounding the episodes. Depending on the circumstances surrounding these episodes, your provider may order the following tests:.
Electrocardiogram ECG. This gives information about your heart rhythm and heart rate. Echocardiogram echo. This shows the structure of your heart, including the valves. Orthostatic vital signs.
This is where your heart rate and blood pressure are measured while you are lying, sitting, and standing. This is to see whether there is a change related to body position. Tilt table testing. With this test you are strapped to a table while lying flat and then steadily brought to a standing position.
These include bradyarrhythmias the heart beats too slowly and tachyarrhythmias the heart beats too fast. Aortic dissection , a tear in the large artery that carries blood from the heart to the rest of the body.
This is a very rare but life-threatening condition. Aortic valve stenosis , a narrowing of the valve between the heart and the aorta.
Aortic valve stenosis can be congenital present from birth or can develop in old age. Reflex syncope is the result of a reflex response to some trigger, in which the heart slows or blood vessels dilate widen. This causes blood pressure to drop, so less blood flows to the brain and fainting syncope or near-fainting pre-syncope occurs. Reflex syncope is the most frequent cause of fainting.
Vasovagal syncope — the common faint — occurs in one third of the population. It is by far the most common form of reflex syncope. Vasovagal syncope is often triggered by a combination of dehydration and upright posture.
But it can also have an emotional trigger such as seeing blood "fainting at the sight of blood". Situational syncope , a sudden reflex response to a trigger other than those listed above. Triggers include:. Carotid Sinus Syncope, a response in older adults that occurs when pressure is applied to the carotid artery in the neck. A hard twist of the neck, wearing a tight collar and pressing on the artery are triggers for carotid sinus syncope.
Orthostatic upright hypotension low blood pressure when standing can also cause fainting because blood has trouble going against gravity to reach the brain. Orthostatic hypotension is defined as a fall in systolic blood pressure of 20 mmg Hg or more on standing, resulting in syncope or pre-syncope.
Orthostatic hypotension is common in elderly individuals and is often exacerbated by dehydration or medications that lower blood pressure, such as diuretics.
Postural orthostatic tachycardia syndrome increased heart rate when standing , or POTS, is a rare clinical syndrome characterized by an increase in heart rate of at least 30 beats per minute on standing and orthostatic intolerance — when standing brings on symptoms such as palpitations, lightheadedness and fatigue. POTS generally appears in young women. After excluding other causes, the diagnosis is made on physical examination, medical history and tilt-table test.
For athletes, a cardiovascular assessment by a healthcare provider is recommended before resuming competitive sports. Those with syncope and a structural heart rhythm disorder should also see a specialist. Extended monitoring may help athletes with unexplained exertional syncope. Standardized national registries and large databases are needed to gather more data to better understand the incidence and prevalence of syncope, patient risks and outcomes, set lifestyle policies and improve healthcare delivery.
Some studies have shown that with recurrent episodes of fainting, the quality of life is reduced in both adults and in pediatric patients, however more well designed studies that incorporates quality of life, work loss and functional capacity are needed. In addition, more studies incorporate quality of life, work loss and functional capacity as possible results and better understand the relationship of syncope symptoms, causes and underlying diseases to various outcomes.
Written by American Heart Association editorial staff and reviewed by science and medicine advisers. See our editorial policies and staff. About Arrhythmia. Why Arrhythmia Matters. Understand Your Risk for Arrhythmia. Symptoms, Diagnosis and Monitoring of Arrhythmia.
Prevention and Treatment. Arrhythmia Tools and Resources. What causes syncope? What is neurally mediated syncope? Other disorders can cause syncope, which also can be a side effect of some medicines. Some types of syncope suggest a serious disorder: Those occurring with exercise Those associated with palpitations or irregularities of the heart Those associated with family history of recurrent syncope or sudden death What is cardiac syncope?
What are the risk factors? Syncope is common, but adults over age 80 are at greater risk of hospitalization and death. AHA Recommendations People who experience the warning signs of fainting of dizziness, nausea and sweaty palms should sit or lie down. Some patients of any age may need medication.
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