2. You\’re really, really nervous (
): This is the classic \”I pass out at the sight of blood\” situation, Dr. Tedeschi says. In reality, it\’s just a reflex controlled by your body\’s vagus nerve, which helps regulate your heart rate. \”When you get a little anxious or excited or revved up about something, your body counteracts that,\” he explains. \”And when your body over compensates, your heart slows down. \” From there, it\’s the same story: Your body can\’t pump enough blood to your brain, and you pass out. Again, this isn\’t usually a sign that something more serious is going on, but it\’s hard to tell without getting checked out by a doctor. Fainting (syncope) is caused by a temporary reduction in blood flow to the brain. Blood flow to the brain can be interrupted for a number of reasons. The different causes of fainting are explained below.
Fainting is most commonly caused by a temporary glitch in the autonomic nervous system. This is sometimes known as neurally mediated syncope. The autonomic nervous system is made upPof the brain, nerves and spinal cord. It regulates automatic bodily functions, such as heart rate and blood pressure. An external triggerPcanPtemporarily causePthe autonomic nervous system to stop working properly, resulting in a fall in blood pressure and fainting. The trigger may also cause your heartbeat to slow down or pause for a few seconds,Presulting in a temporary interruptionPto the brain\’s blood supply. This is called vasovagal syncope. sitting or standing up suddenlyP known asP Fainting can also be caused by aPfall in blood pressure when you stand up. This is called orthostatic,Pand tends to affectPolder people, particularly those aged overP65.
It\’s a common cause ofP inPolder people. When you stand up after sitting or lying down, gravity pulls blood down into your legs, which reduces your blood pressure. The nervous system usually counteracts this by making your heart beat faster and narrowing your blood vessels. This stabilises your blood pressure. However, in cases of orthostatic hypotension, this doesn\’t happen, leading to thePbrain\’s blood supply being interrupted and causing youPto faint. PPif you\’re dehydrated, the amount of fluid in your blood will be reduced and your blood pressure will decrease; this makes it harder for your nervous system to stabilise your blood pressure andPincreases your risk of fainting Puncontrolled diabetes makes you urinate frequently, which can lead to dehydration; excess blood sugar levels can also damage the nerves that help regulate blood pressure medication PPany medicationPforP and any neurological conditions Pconditions that affect the nervous system, such as, can trigger orthostatic hypotension in some people Heart problems can also interrupt the brain\’s blood supply and cause fainting.
This type of fainting is called cardiac syncope. The risk of developing cardiac syncope increases with age. You\’re also at increased risk if you have: narrowed or blocked blood vessels to the heart chest pain had aP structural problems with the muscles of the heart See your GP as soon as possible if you think your fainting is related to a heart problem. A reflex anoxic seizure (RAS) is a type of fainting that mainly occurs in young children.
It\’s caused by an involuntary slowing of the heart rate, to the extent that the heart actually stops beating for 5-30 seconds. The child will often open their mouth as if they\’re going to cry, but make no sound before turning pale grey and losing consciousness. They\’ll either become limp Por, more often, stiffP with their eyes rolling upwards and their fingers clawed. Their body may also jerk a few times. The seizure usually lasts less than a minute. Afterwards, the child will regain consciousness, but may appear sleepy and confused for a few hours. Reflex anoxic seizures can be frightening to witness, but they aren\’t dangerous and don\’t harm the child. The seizures will become less frequent as the child gets olderPand usually disappear by the time they\’re four or five years of age. Read more about.