Which of the following is a sign of hypokalemia?

Muscle weakness is a classic sign of hypokalemia, which refers to lower than normal potassium levels in the bloodstream. Potassium is an essential electrolyte that plays a critical role in muscle contraction and overall neuromuscular function. When potassium levels drop, patients often experience muscle weakness, particularly in the proximal muscles, such as those in the thighs and hips.

This symptom occurs because inadequate potassium affects the electrical activity of muscle cells, leading to impaired contractions and weaknesses.

While increased urination and elevated heart rate can be associated with various conditions, they are not specific indicators of hypokalemia. Additionally, retained gastrointestinal motility is not aligned with symptoms of hypokalemia, as hypokalemia can often lead to decreased gastrointestinal motility instead. Thus, the identification of muscle weakness is crucial for recognizing hypokalemia in a patient.