Aim:To investigate the correlation between Body Mass Index (BMI) and sympathetic function in adult males using the Cold Pressor Test (CPT). Material and Methods: The research recruited 80 volunteers between the ages of 18 and 30 years, with a body mass index (BMI) ranging from 18 to 30 kg/m2.The cuff was fastened securely around the dominant upper arm, about 2-3 cm above the elbow. Next, thess stethoscope's bell was gently placed above the brachial artery and the air pump was compressed, causing the mercury level to rise to 40-50 mmHg above the systolic level obtained by the palpatory approach. The pressure was gradually reduced until a distinct rhythmic sound was detected, and the blood pressure was measured using the auscultatory technique.The subject's dominant arm was submerged in icy cold water and within one minute, systolic and diastolic blood pressure were recorded. Results:With normal BMI, 12 subjects were normal SBP, 37 subjects were pre-hypertensive and 1 subject was stage 1 hypertensive. In overweight, 1 subject was normal ,9 subjects were pre-hypertensive and 1 subject was stage 1 hypertensive. In obese, 2 subjects were normal, 11 were pre-hypertensive and 6 subjects were stage 1hypertensive.With normal BMI, 16 subjects were normal DBP, 31 subjects were pre- hypertensive and 3 subjects were stage 1 hypertensive. In overweight, 2 subjects were normal, 7 subjects were pre- hypertensive and 2 subjects were stage 1 hypertensive. In obese, 3 subjects were normal, 6 subjects were pre-hypertensive, 8 subjects were stage 1 hypertensive and 2 subjects were stage 2 hypertensive. Conclusion:After doing the Cold pressor test, we determined that there was an increase in sympathetic activity among those who were overweight or obese compared to those with a normal body mass index.