Itchy eyes? Sneezing? Immune reaction or overreaction? What really happens in hay fever and pollen allergy
- Mar 25, 2024
- 3 min read
Updated: Mar 3
Itchy eyes.
Sneezing that won’t stop.
A heavy fatigue that feels like a lingering cold.
For many people, these are clear signs that pollen season has begun. But what is actually happening in the body when hay fever or pollen allergy flares up?
To understand it clearly, we need to separate two thing: the immune reaction itself and what might be described as an overreaction.
The immune reaction: the body’s protection system
The immune system exists to protect you.
Its role is to recognise potential threats — such as viruses and bacteria — and respond quickly.
In pollen allergy (hay fever), the immune system mistakenly identifies pollen as a threat, even though is harmless. As a result, the body activates a defence response.
This can lead to symptoms such as:
Runny or blocked nose
Itchy, red eyes
Sneezing
Fatigue
From a biological perspective, this is a real immune response. The body is doing what it believes is necessary to protect you.
When does a reaction become an overreaction?
Here is where it becomes interesting.
People respond differently to pollen.
Some barely notice it.
Others are significantly affected.
The intensity of symptoms does not depend only on how much pollen is in the air. It also depends on how sensitive the body’s protection system is set.
The immune reaction is present — but the strength of that reaction can vary.
The body learns patterns. Learns how to respond. When a reaction is repeated year after year, it can become faster and more intense — automatic.
So in hay fever, there is an immune response. But sometimes the body may have learned to respond very strongly to pollen. In those cases, the protection system may be easier to trigger than it realisticly is necessary.
The nervous system also influences sensitivity
The immune system does not operate alone. It is in constant communication with the nervous system.
The nervous system functions somewhat like a setting that influences how strongly the body responds. If that setting is high, reactions may occur more quickly and intensely.
When the system is more balanced, the reaction may be calmer.
How it connects
The body detects pollen ↓ The protection system activates ↓ The nervous system’s sensitivity influences intensity ↓ Symptoms appear
The strength of the reaction therefore depends not only on pollen exposure, but also on how sensitive the system is set.
The body learns - and can sometimes re-learn
One important aspect of the human body is its adaptability.
The brain and nervous system continuously change through what is known as neuroplasticity.
The body learns how to respond. And what has been learned can, in some cases, be relearned.
This does not mean “thinking away” an allergy. But it does mean that the intensity of the body’s response may be influenced.
Relearning
↓
Adjusted sensitivity level
↓
Less intense reaction
Summary
Hay fever and pollen allergy involve an immune reaction.
However, the intensity of that reaction is influenced by how sensitive the body’s protection system has become.
The body reacts in order to protect.
The key question is how strongly it needs to respond.
If you struggle with hay fever or grass pollen allergy, you can read more about how we work with the body’s reaction patterns here.
