hhumans can smell over 1 trillion odors, But no two people will react the same way to the same smell. While there are some odors nearly everyone agrees are unpleasant (such as paint thinner or rotten food), our reactions to other types of odors can be far more individual.
Take perfume While one person may find the smell of a strong, floral perfume heavenly, another person may find that it gives them a headache. There are many reasons why people may have a physical reaction to a strong smell – but here are three of the most common.
1. Emotions
Of all our senses, only smell has a straight line. our emotional system, It is believed that the reason for this link is that smell is one of the first of our senses to develop. This means that we do not perceive odors solely on the basis of odorous chemicals presented to us, but in combination with all our memories of that smell – the way it makes us feel, our past memories, and how we feel in the present.
So let’s say you smell something that you associate with a negative memory. Maybe it’s the smell of cleaning chemicals used in a hospital, or the same perfume your ex used. may cause a tremor all those negative feelings to move your body forward, to come back to you running induce fight or flight stress response,
The fight or flight stress response is your body’s way of reacting to stress, anxiety or danger. This causes a number of physiological changes, most of which are triggered by the brain going into high alert. One of the first changes you may notice during a fight or flight response is tension around the head and neck. This is due to vasodilation (widening of the blood vessels) which allows more blood to move to the brain and parts of the body that need it.
Vasodilation also activates sensory receptors embedded in blood vessels, which we experience as a headache Pain if the blood vessels in the head and neck are dilating.
How we react emotionally to certain odors is very individual, and based on a myriad experiences, It can also be triggered by smells we may not even be conscious of smelling or consciously aware of our response to them. But if you get headaches only when you smell certain odors, it could be because of your negative association.
2. Sinus trouble
Chemicals that activate odor signals in our brain (called odorants) can sometimes irritate our sinuses. Smoke, perfume and chlorine are the most common odors that cause irritation.
Our sinuses consist of four separate, air-filled pores in the bones of our face. Each are lined with a mucous-secreting membrane. Mucus traps particles and insects that come in through our nose and mouth. But to clear away these trapped particles or potential irritants, the body needs to produce more and more mucus—resulting in allergy-like symptoms. This in turn causes our immune system to kick in and help, resulting in vasodilation and inflammation. For some the end result is a headache,
there may be some smell act directly on nerve pathways Which also transmits sensory signals to the brain. Called the trigeminal pathway, it takes in all sensory signals from our head and carries them through nerve cells to the brain for processing.
When this pathway is stimulated it causes inflammation as it detects a threat that only the immune system can address. It can also cause headache. Chemical odors such as formaldehyde, some cleaning products and cigarette smoke are all known to act directly on the trigeminal pathway.
3. Odor intolerance
Osmophobia is defined as an intolerance to odors. While rare in itself, people who suffer from chronic headaches also experience osmophobia.
are migraine sufferers particularly prone to osmophobia, Some research has also shown that exposure to strong odors for two hours or more can actually trigger migraines. About 20% of migraine sufferers, Some of the most common triggering scents are cigarette smoke, perfume, car exhaust, and cleaning products.
The nervous system of a person experiencing a migraine may be particularly sensitive to certain sensory stimuli in their daily life. But during the prodrome phase (the first of four distinct phases of a migraine, which can occur days or hours before a headache attack) they can become more sensitive to certain stimuli Including the smell.
Many migraine sufferers experience certain signs that a migraine is coming during the podrome phase – such as yawning more and craving certain foods. Smells that usually wouldn’t bother you, might too bothered you badly, You may also perceive smells that are not there – known as phantom smell, The most common phantom odor many report before a migraine is a burning smell. So while the smell is not a migraine trigger in this instance, it could be a sign of an oncoming headache.
Science has not yet found any effective way to avoid it. So, if you’re one of those people who get headaches from certain smells (for whatever reason), it’s best to avoid them as much as possible. But since we can’t always avoid triggers, fresh air and painkillers may be the best way to manage any headaches that do occur.
Amanda Ellisonprofessor of neuroscience, Durham University
This article is republished from Conversation Under Creative Commons license. read the original article,
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