Background information Tuberculosis (TB) is one of the major public health problems in Pakistan. Our country ranks fifth in tuberculosis high, burden countries worldwide. Hyponatremia is considered as one of the most common and important electrolyte abnormality in Pulmonary TB (P TB) patients. This study will show the prevalence of hyponatremia in PTB in our population. This study was planned to determine the presence of hyponatremia in pulmonary tuberculosis among adults and to correlate its severity. Materials and Methods It is a hospital based cross sectional study conducted with 65 patients. Symptomatic microbiologically confirmed case of pulmonary tuberculosis, admitted in Yenepoya Medical College Hospital and are willing to participate in the study will be enrolled after counselling. The study will be explained to participants and care providers after which informed consent will be taken from each participant. The study period is for 5 months.