A normal person takes almost 25,000 breaths per day. Lung diseases are broadly classified into ‘Obstructive’ and ‘Restrictive’ diseases. In Obstructive lung diseases, the patient feels difficulty in breathing, more so on increased physical activity e.g. exercise. Patients with obstructive diseases develop shortness of breath because they lack the ability to exhale whole air from lungs. This happens because either the lungs get damaged or the airways get narrowed. In Restrictive lung diseases, the patient is unable to inhale properly so the lungs are not completely filled with air and they cannot expand to their full extent. This is mainly caused by the rigidity of lung tissues.

Obstructive Lung Diseases

It is a group of diseases that are associated with narrowing of smaller airways i.e. bronchi and bronchioles. Various causes include tobacco smoking, the continual infective process of lungs, and immunity based diseases. Different examples of these diseases include asthma, COPD (chronic obstructive lung diseases), bronchitis, and bronchiectasis.

Restrictive Lung Diseases

This is a group of diseases in which lungs cannot expand properly because of the restrictive effect of extrapulmonary tissues. The patient presents with complaints of chronic cough and dyspnea (shortness of breath). Causative factors are occupational exposure to hazardous compounds, certain drugs like Methotrexate, and radiation exposure. Conditions that cause restrictive lung diseases are interstitial lung diseases, sarcoidosis (an autoimmune disease), and obesity.

Types:

Restrictive lung diseases are divided into two types i.e extrinsic and intrinsic. Intrinsic restrictive lung disorders (parenchymal disease) lead to an internal defect involving the lung tissues, making them inflamed and scarred. Examples include pneumonia, tuberculosis, sarcoidosis, etc.

Extrinsic Restrictive lung disorders (non-parenchymal disease) involve pleura, chest wall, and the respiratory muscles. Examples include pleural effusion, scoliosis, myasthenia gravis, etc.

Obstructive VS Restrictive Lung Diseases

Pathophysiology:

Obstructive lung diseases have narrowed air passages that limit the outflow of air from the lungs. This results in increased airway resistance.

Restrictive lung diseases have limited expansion of lungs due to restriction of surrounding structures causing decreased lung or thoracic compliance.

Anatomic defect:

In Obstructive lung diseases, the airway is affected.

In Restrictive lung diseases, lung tissue or thorax is affected.

Diagnosis:

Both the diseases are diagnosed on the basis of the results of ‘pulmonary function tests’. Forced expiratory volume is the ability to exhale as much as you can in one second. Forced vital capacity is the amount of air that can be forcefully exhaled after a deep breath.

In Obstructive lung diseases, total lung capacity is normal, and forced vital capacity is normal but the expiratory flow rate is decreased. FEV1/FVC ratio is <0.7.

In Restrictive lung diseases, total lung capacity and forced vital capacity are reduced but the expiratory flow rate is normal. FEV1/FVC ratio is >0.7.

Other than spirometry, chest x-ray, CT scan and blood tests (ABGs more importantly) must be done to reach the diagnosis.

Prevention:

Obstructive lung diseases can be prevented by avoiding smoking or second-hand smoking, exercising, and taking precautions when you’re exposed to dust, irritants, chemicals, or fumes.

Restrictive lung diseases can be prevented by avoiding smoking, having a nutritious diet, respiratory muscle strength exercises, etc.

Treatment:

Medical treatment of the obstructive lung diseases includes steroids and bronchodilators.

Some patients may require oxygen therapy through a mask or nasal cannula.

Surgical treatment includes removal of the damaged lung tissues and the abnormal air spaces (bullectomy).

Restrictive lung diseases are treated through immunosuppressant drugs and steroids. Oxygen therapy is also needed in some cases. In severe conditions, lung transplant or stem cell therapy is also recommended.

Examples:

Obstructive lung diseases include asthma, COPD, Bronchitis, and bronchiectasis.

Restrictive lung diseases include interstitial pneumonia, sarcoidosis, cystic fibrosis, pulmonary fibrosis, and pneumoconiosis (pneumonia due to occupation chemicals)

Conclusion

Depending on the causative process, lung diseases have two categories. Both groups of diseases have troublesome impacts on one’s daily activities because patients have difficulty in  breathing. The diseases can be prevented by avoiding the factors leading to diseases. Prevention is better than cure because there is no ultimate treatment for these but lifelong pharmacological drugs administration or lung transplant.

References:

https://www.medicalnewstoday.com/articles/318905#treatment

https://www.lung.ca/lung-health/lung-disease/copd/diagnosis

https://lunginstitute.com/blog/the-difference-between-obstructive-and-restrictive-lung-disease/

https://www.verywellhealth.com/obstructive-and-restrictive-lung-diseases-914741

https://www.healthline.com/health/copd