The purpose of the study is to evaluate the hypothesis of poor clinical outcomes in critically ill patients that are having abnormal BMI.

All demographic data will be obtained including the patients' age, sex, body mass index (BMI) & categorized into; BMI < 18.5Kg/m2 = underweight, BMI between 18.5-24.9Kg/m2 = normal weight, while BMI between 25-29.9Kg/m2 = overweight & obese = BMI ≥ 30Kg/m2, associated co-morbidities (diabetes mellitus, hypertension, chronic renal failure, cancer& chronic liver disease), the cause of admission to ICU, Sequential Organ Failure Assessment (SOFA), nutritional risk screening (NRS) on admission & discharge, prior cardiac arrest, previous ICU admission within 6months, nosocomial infection, organ failure e.g. cardiovascular, respiratory, renal & organic support requirement e.g. hemodynamic support, mechanical ventilation, renal replacement therapy (RRT).

Inclusion Criteria:

• Patients who are admitted to the intensive care unit of National Hepatology & Tropical Medicine Research Institute (NHTMRI) for medical & surgical indications during the period from February 2018 to December 2020.

Exclusion Criteria:

• Patients will be excluded if they have stayed in ICU ≤24 hours and underweight (BMI<18.5).

Patients that will be admitted to ICU will be categorized into; BMI < 18.5Kg/m2 =underweight, BMI between 18.5-24.9Kg/m2 = normal weight, while BMI between 25-29.9Kg/m2 = overweight & obese = BMI ≥ 30Kg/m2