Bronchial asthma affects more than a quarter of a billion people worldwide. It is responsible for over 1000 deaths a day, of which the majority are preventable (Levy, 2015).

Asthma is a common heterogeneous disease characterized by chronic airway inflammation. It is defined by the history of variable respiratory symptoms, such as shortness of breath, chest tightness, wheezes, and cough, together with variable expiratory airflow limitation. Airflow limitation may later become persistent (GINA, 2023).

The diagnosis of asthma is based on the history of these characteristic symptoms and evidence of variable expiratory airflow limitation from bronchodilator reversibility testing or other tests (GINA, 2023).

Inclusion Criteria:

• All patients were admitted to Sohag University Hospital, chest department DIAGNOSED AS BRONCHIAL ASTHMA

Exclusion Criteria:

• Patients with malignancies, major trauma or surgery, and acute or chronic infectious diseases were excluded.

The study was case control had included 97 asthma patients and 97 healthy controls. The asthmatic patients will cautiously select from those attending the respiratory consultant clinics at Sohag University Hospital diagnosed with asthma (with no history of respiratory infections) PFT was performed with a spirometer (PHILIPS). The primary purpose of it was to confirm the diagnosis of asthma. Pre- and post-bronchodilator spirometer measurements will be performed in all study subjects and forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC) values and FEV1/FVC ratio will be