Things that cause your blood pressure to drop can be as simple as nutritional deficiencies or being dehydrated. One of the most common causes is blood loss. Slightly rarer, and a little more complex, is a neurological cause. This is known as reflex syncope.
There are three types of reflex syncope: vasovagal, situational and carotid sinus. All three involve the lowering of your blood pressure and/or heart rate. Unlike postural hypotension, it’s not affected by you standing up and sitting down. It can occur when you’re seated or standing in a steadily upright position.
First you may experience lightheadedness. There may be sweating and changes in body temperature, whether hot or cold. It can affect eyesight, causing blurred vision, seeing spots or other distorted perception. You may hear ringing in your ears. Thoughts and speech may become fuzzy. Eventually, you’ll lose consciousness, though probably only briefly.
The most serious risk with reflex syncope is that you could cause yourself an injury when you fall. Once your body is flat, normal blood flow will be restored and you should regain consciousness quickly. If your head is slightly elevated after the fall, your muscles may twitch while you’re unconscious.
Reflex syncope is a nervous system disorder. It responds to certain triggers by slowing your heart rate and narrowing your blood vessels so less blood reaches the brain. The type of trigger depends on the type of reflex syncope, but in all cases, management includes trying to avoid encountering those triggers again.
Vasovagal syncope is normally triggered by pain, the sight of blood, emotional distress or standing for a long time. If you faint when you see needles, that may be vasovagal syncope. It can also be associated with changes in the brain’s magnetic field.
Situational syncope is often triggered by certain movements. Lifting heavy objects or even coughing and swallowing can cause it. It could even involve straining for a bowel movement or micturition syncope (during or just after urination).
Third is carotid sinus, which only has one cause: pressure on a certain spot on your neck. This pressure can occur when shaving, wearing a shirt or jacket with a tight collar or even if you turn your neck in a certain way.
You’re unlikely to experience serious injury from reflex syncope, but it helps to recognize the triggers and try to restore blood flow quickly.
