What are possible causes of a low potassium level?

QUESTION 13:
Chapter 13, Fluid and Electrolytes: Balance and Disturbance
Mrs. Dean is 75-year-old woman admitted to the hospital for a small bowel obstruction. Her medical history includes hypertension. Mrs. Dean is NPO. She has a nasogastric (NG) tube to low continuous suction. She has an IV of 0.9% NS at 83 mL/hr. Current medications include furosemide 20 mg daily and hydromorphone 0.2 mg every 4 hours, as needed for pain. The morning electrolytes reveal serum potassium of 3.2 mEq/L. (Learning Objective 4). Nursing Questions & Answers .
a. What are possible causes of a low potassium level?
b. What action should the nurse take in relation to the serum potassium level?
c. What clinical manifestations might the nurse assess in Mrs. Dean?