This is so vague. Many several factors can cause hypotension.
Most common cause is cardiac tamponade. Other causes pulmonary embolism , tension pneumothorax, acute arrhythmias, MI , Fulminant sepsis .
History of present illness and past medical history may be helpful. Medications? Previous Surgery? Things to be ruled out Cardiac tamonade: low altitude ecg and echo PE: CTPA Sepsis: blood analysis and culture And Shock: Low blood pressure Tachycardia