The practice of holding a chemical irritant, such as an ammonia salt capsule or a strong sniff of rubbing alcohol, under a person’s nose is often depicted in movies and books. This folk remedy is intended to “snap” a person out of a pre-fainting state, which is medically known as presyncope. This method produces a strong physiological response, but it does not address the root cause of the dizziness.
The Immediate Physiological Reaction to Irritant Smells
Irritant chemicals like ammonia and high-concentration alcohol do not stimulate the sense of smell directly. Instead, they activate the trigeminal nerve, the fifth cranial nerve responsible for sensation in the face. This nerve contains receptors that respond to painful or irritating chemical stimuli, sending a strong signal directly to the brainstem.
This sudden jolt is a defensive, involuntary reflex that causes a brief, sharp arousal response. The purpose of this reflex is to interrupt the body’s process of fainting, such as a vasovagal syncopal episode where heart rate and blood pressure drop sharply. While this stimulation may prevent temporary loss of consciousness, modern medical practice prefers safer, less abrasive methods that support the body’s natural regulation of blood flow.
Common Causes of Dizziness and Fainting
Dizziness and feeling faint, or presyncope, most often occur when the brain temporarily receives an insufficient supply of oxygenated blood. A common cause is orthostatic hypotension, a temporary drop in blood pressure that happens when a person stands up too quickly. Gravity pulls blood to the lower extremities, and the body’s reflexes do not compensate fast enough to maintain pressure to the head.
Dehydration and overheating are also frequent contributors, as reduced blood volume makes it difficult to maintain adequate circulation. Another common event is vasovagal syncope, where a trigger like intense emotional stress or pain causes the vagus nerve to slow the heart rate and dilate blood vessels. Inner ear disturbances, such as benign paroxysmal positional vertigo (BPPV), cause a spinning sensation called vertigo, which is distinct from lightheadedness.
Proven First Aid Steps for Managing Dizziness
The most effective first aid for managing dizziness or a pre-fainting episode focuses on restoring proper blood flow to the brain without shock. If someone begins to feel faint, they should immediately sit down and place their head between their knees. This positioning uses gravity to increase blood flow back to the head.
If possible, have the person lie flat on the floor and elevate their legs above the level of the heart. This technique promotes venous return, quickly increasing the volume of blood available to the brain. Slow, deep breathing exercises can help regulate the nervous system, especially if the episode is related to anxiety. If the person is conscious and able to swallow, offering water can help address potential dehydration, but all movements should be slow and deliberate until the symptoms pass.
Warning Signs Requiring Medical Attention
While many instances of dizziness are temporary and benign, certain accompanying symptoms indicate a serious medical situation that requires immediate emergency evaluation. Seek urgent medical care if dizziness is accompanied by a sudden, severe headache or chest pain. These combinations can be warning signs of a stroke or a heart problem, which require time-sensitive treatment.
Other red flags include the sudden onset of difficulty speaking, slurred speech, or weakness and numbness in the face, arms, or legs. Any episode of dizziness that occurs immediately following a head injury, or is associated with a rapid or irregular heartbeat, should prompt an emergency call. Fainting, loss of consciousness, seizures, or double vision are also indicators that a person needs professional medical attention without delay.