How can a deficiency in potassium manifest symptomatically?

A deficiency in potassium can manifest symptomatically through fatigue and irregular heart rhythms due to the critical role potassium plays in maintaining proper muscle function, including that of the heart. Potassium is essential for the conduction of electrical signals in the body, which is crucial for muscle contractions and maintaining the heart's rhythm. Low potassium levels, also known as hypokalemia, can lead to muscle weakness and cramping, and in severe cases, arrhythmias or irregular heartbeats.

The other options reflect conditions and symptoms that do not specifically relate to potassium deficiency. High blood pressure and cholesterol are more often associated with overall diet and lifestyle rather than a specific deficiency. Increased appetite and weight gain can relate to various factors, including hormonal changes or lifestyle choices, and do not derive directly from a lack of potassium. Joint inflammation and pain are usually linked to issues such as arthritis or other inflammatory conditions, rather than electrolyte imbalances like potassium deficiency.