Introduction

A brief overview of asthma

Asthma is a chronic lung condition that results from inflamed and narrowed airways in the lung, which may also produce extra mucous.¹ The most common symptoms of asthma are:¹

• Difficulty breathing 
• Wheezing
• Chest tightness 
• Coughing

Diagnosis for asthma involves numerous tests, to assess how fast you can breathe out and how much air you can hold in your lungs (spirometry and peak flow test) and the level of nitric oxide in your breath (FeNO test).² Following these assessments, an X-ray might also take place to test for any allergies that may trigger your symptoms.³

Asthma is caused by several factors such as genetics, allergies, environmental factors (e.g. exposure to tobacco), infection (e.g. COVID-19), lifestyle and so on.¹ Asthma affects about 262 million people worldwide (data from 2019) and 4.3 million people in the UK specifically. 

The link between emotional health and asthma exacerbations

Asthma exacerbation or asthma attack is a flare-up of your symptoms that may require treatment. During this episode, airways become more narrow and inflamed resulting in decreased baseline objective measures of pulmonary functions, such as FEV1 and peak expiratory flow rate.⁴ Severe exacerbation can lead to hospitalization or even death. Some common triggers include infection, allergens, pollutants and emotional stress.¹

There is increasing evidence supporting the impact of stress on asthma and asthma exacerbation.⁵ Furthermore, exacerbation of symptoms can cause further stress and you would end up in a vicious cycle. Therefore, understanding the link between asthma exacerbation and stress is extremely important.⁵

The physiological impact of stress and anxiety on asthma exacerbation

Fight-or-flight response

When you are stressed, your sympathetic nervous system activates your hypothalamic pituitary adrenal (HPA) axis⁶ which results in the release of several hormones and eventually cortisol. Cortisol regulates your stress response by using your body’s fat, carbohydrate and protein. It regulates your heart rate, blood sugar, blood pressure and inflammation.⁶

Your HPA axis has a feedback loop, meaning cortisol can also activate your HPA axis resulting in the production of more cortisol.⁶ Therefore, during chronic stress where your stress response persists, you get an excess and dysregulated level of cortisol. Increased levels of this hormone can cause insensitivity, therefore, reducing its anti-inflammatory effects. So if you have asthma, the lack of anti-inflammatory effects of cortisol, results in increased inflammation in your airways, and consequently, asthma exacerbation.⁷

Inflammatory response

The excess cortisol also suppresses your immune system, leading to decreased levels of your pro-inflammatory cytokines - molecules that cause inflammation to fight infection - by reducing the activity of some important immune cells such as B-cells and T-cells. This will cause your body to become weakened and unable to fight infections and respond to vaccines.⁸ This is detrimental to your asthma exacerbation as some infections result in inflammation in the airways, and increased sensitivity of your airways - so more sensitive to asthma triggers such as allergens, smoke etc. - thickened mucous and so on.

Hyperventilation

During periods of stress, your body activates its HPA axis which results in your stress response as explained above. However, anxiety attacks, which are sudden intense periods of stress, can lead to hyperventilation.⁸ Hyperventilation is when you breathe out too much carbon dioxide in a short period leading to decreased carbon dioxide levels and therefore shortness of breath. If you have asthma, this shortness of breath can cause further anxiety for you, creating a cycle of hyperventilation and eventually asthma attack.⁹ 

Bronchoconstriction

During stress, your parasympathetic nervous system may also activate and release acetylcholine - a hormone and neurotransmitter - which might bind to your receptors in your airway causing them to contract, leading to narrowing of the airways otherwise known as bronchoconstriction and eventually asthma exacerbation.¹⁰

Managing stress and anxiety to reduce asthma exacerbations

Effective stress management is crucial for reducing the severity and frequency of asthma exacerbation. Here are some key ways to help you manage your stress levels. 

Stress management techniques

Relaxation techniques: Practices such as meditation and breathing exercises can help you relax your mind and body. 

Cognitive-behavioural therapy (CBT): a therapeutic approach that can help you reduce your stress levels especially if you are suffering from chronic stress. 

Pharmacological interventions

Anti-anxiety medications are also an effective way of managing stress. The most commonly used family anxiolytics are serotonin reuptake inhibitors (SSRIs). Any pharmacological intervention must be under medical supervision.¹¹ 

Summary

Chronic and acute stress can both result in increased frequency and severity of asthma exacerbation mainly due to the effect that different hormones have when released as a result of your HPA-axis activating. Furthermore, you might experience hyperventilating following an anxiety attack that results in decreased carbon dioxide levels and thus shortness of breath. Therefore, managing stress in patients suffering from asthma holds significant importance.