Introduction: Pulmonary function tests (PFTs) is a generic term used to indicate a battery of studies or manoeuvres that may be performed using standardized equipment to measure lung function. PFTs can include simple screening spirometry, formal lung volume measurement, diffusing capacity for carbon monoxide, and arterial blood gases. These studies may collectively be referred to as a complete pulmonary function survey.

Methodology: Information was collected through a pre tested and structured proforma for each patient Qualifying patients will be undergoing detailed history, clinical examination, routine investigations like FBS, PPBS, HBA1c, fundus evaluation and spirometric evaluation using a easy one flow spirometer. Glycemic control is taken as HBA1C below 7.5 and HBA1C more than 7.5 is considered as uncontrolled sugars Diabetic patients of different durations are selected Using criteria laid down.

Results: In our study, 2(10%)patients with HBA1C <7.5 had restrictive pattern and out of 15 patients with HBA1C of more than 7.5, 10(20%) patients had restrictive pattern in group 1 where as in group 2, 6 patients with HBA1C >< 7.5 had restrictive pattern and out of 26 patients with HBA1C >7.5, restrictive pattern was seen in 21 patients in group 2.

Conclusion: Spirometry is the most commonly used lung function screening study. It generally should be the clinicians first option.