Why people faint: From common to very rare causes

There’s one simple reason behind all fainting episodes — the brain isn’t getting enough blood. But there are many possible underlying causes, ranging from common, usually harmless issues to rare, potentially serious problems.

“Fainting always should be taken seriously, so be sure to get evaluated by a doctor if you faint, particularly if you have any history of heart problems,” says Dr. Jeremy Ruskin, founder of the arrhythmia service at Harvard-affiliated Massachusetts General Hospital. But even people without any previous heart issues aren’t off the hook. Sometimes syncope (the medical term for fainting) is the first sign of a previously undetected heart condition, he says.

The heart of a fainting episode

Cardiac syncope accounts for only about 15% of all fainting episodes — far fewer than reflex syncope, the most common type (see “When the nervous system overreacts: Reflex syncope”). Cardiac syncope is the most serious form of fainting, however, because it may be a harbinger of sudden death.

Heart-related causes of fainting usually result from an electrical problem that causes the heart to beat either too slowly or too quickly, says Dr. Ruskin. These so-called arrhythmias may be caused by damage from a heart attack or heart muscle disease (cardiomyopathy). Both can disrupt the electrical system of the heart and reduce its ability to pump effectively. Other causes include genetic abnormalities in the heart’s electrical system, such as long QT syndrome or Brugada syndrome. Finally, conditions that can reduce blood flow and trigger fainting include a stiffening of the aortic valve (aortic stenosis) or narrowing of the outlet of the left ventricle from hypertrophic cardiomyopathy.

When the nervous system overreacts: Reflex syncopeAt least half of all fainting episodes stem from an overly sensitive response by the nervous system known as reflex syncope. In all cases, the nervous system tells the heart to slow down and the blood vessels to dilate, which lowers blood pressure and diminishes blood flow to the brain. The most common type, vasovagal syncope, refers to the effects of the vagus nerve (which regulates heart rate and blood pressure, among other things). It occurs when your body overreacts to emotional distress or the sight of blood, or during situations that overstimulate the vagus nerve, such as having a bowel movement, coughing, or swallowing.Carotid sinus hypersensitivity is a rare cause of syncope that occurs in response to pressure — caused by wearing a tight collar or shaving, for example — on a certain spot in the neck. The pressure stimulates structures called baroreceptors that activate hormone and nerve signals to regulate blood pressure. Older people (usually men) with plaque buildup in the carotid arteries are most likely to experience this hypersensitivity.

A sudden pressure drop

Another common reason people faint involves a sudden drop in blood pressure that occurs upon standing, known as postural or orthostatic hypotension. During these episodes, blood pools in the lower part of your body. Less blood returns to the heart, lowering blood pressure and reducing blood flow to the brain. Common causes include medications to treat high blood pressure or an enlarged prostate gland, and nerve damage or dysfunction (neuropathy) from diabetes, Parkinson’s disease, or other illnesses. Being too warm, not drinking enough water, anxiety, and hunger can aggravate the problem.

A rare twist

The narrowed arteries that are the hallmark of cardiovascular disease occasionally affect the vessels that supply the back of the brain, causing a condition called vertebrobasilar insufficiency (VBI). “This condition reduces blood flow to the back of the brain, a region that’s critical for maintaining balance and consciousness,” says Dr. Ruskin. But VBI can also strike people with wide-open arteries who have bone spurs from arthritis near those neck arteries. Twisting the neck can cause the spur to compress the vessel and obstruct blood flow. This problem, known as rotational vertebral artery syndrome or “bow hunter syndrome,” is very rare.

Uncovering the cause

A detailed history from the patient and witnesses provides the best clues for identifying the underlying cause of a fainting episode, says Dr. Ruskin. If you faint, make a note of any circumstances or symptoms you experienced around that time. Testing always includes a recording of the heart’s electrical activity (electrocardiogram, or ECG) and a heart ultrasound (echocardiogram) to check for structural changes in the heart. Many people will also need longer-term ECG monitoring with special devices or additional tests.

Bible verses for today’s meditation and inspiration: Matthew E. McLaren

2 Corinthians 13:9 For we rejoice when we ourselves are weak but you are strong; this we also pray for, that you be made complete.

Colossians 1:28 We proclaim Him, admonishing every man and teaching every man with all wisdom, so that we may present every man complete in Christ.

Colossians 4:12 Epaphras, who is one of your number, a bondslave of Jesus Christ, sends you his greetings, always laboring earnestly for you in his prayers, that you may stand perfect and fully assured in all the will of God.

2 Corinthians 10:15-16 not boasting beyond our measure, that is, in other men’s labors, but with the hope that as your faith grows, we will be, within our sphere, enlarged even more by you, so as to preach the gospel even to the regions beyond you, and not to boast in what has been accomplished in the sphere of another.

2 Thessalonians 1:3 We ought always to give thanks to God for you, brethren, as is only fitting, because your faith is greatly enlarged, and the love of each one of you toward one another grows ever greater;

2 Peter 3:18 but grow in the grace and knowledge of our Lord and Savior Jesus Christ To Him be the glory, both now and to the day of eternity. Amen.

Ephesians 1:17-18 that the God of our Lord Jesus Christ, the Father of glory, may give to you a spirit of wisdom and of revelation in the knowledge of Him. I pray that the eyes of your heart may be enlightened, so that you will know what is the hope of His calling, what are the riches of the glory of His inheritance in the saints,

Ephesians 3:16-19 that He would grant you, according to the riches of His glory, to be strengthened with power through His Spirit in the inner man, so that Christ may dwell in your hearts through faith; and that you, being rooted and grounded in love, may be able to comprehend with all the saints what is the breadth and length and height and depth, read more

Recommended contacts for prayer request and Bible study








It Is Written

Be the first to comment

Leave a Reply

Show Buttons
Hide Buttons