What are the symptoms of hypokalemia?

　　Hypokalemia is a metabolic disorder caused by abnormally low levels of potassium in the blood, often associated with inadequate potassium intake or excessive potassium loss. Symptoms worsen as serum potassium levels decrease and mainly include neuromuscular symptoms, gastrointestinal discomfort, cardiovascular abnormalities, urinary system manifestations, and signs related to metabolic alkalosis. A detailed analysis is as follows:

　　1. Neuromuscular symptoms: These typically begin in the lower limbs and gradually spread upward. Early symptoms include leg weakness, soreness, and heaviness, with difficulty walking, climbing stairs, or rising from a squatting position. As the condition progresses, muscle cramps and pain may develop. In severe cases, the upper limbs are also affected, manifesting as difficulty lifting the arms, and in extreme situations, flaccid paralysis of all four limbs may occur.

　　2. Gastrointestinal discomfort: Low blood potassium slows gastrointestinal motility, leading to poor appetite, nausea, persistent bloating, dry and hard stools causing constipation, and in some individuals, palpable distended gas pockets in the abdomen. Severe hypokalemia may trigger paralytic ileus, characterized by severe abdominal pain, vomiting, and cessation of flatus and bowel movements.

　　3. Cardiovascular abnormalities: Increased myocardial excitability leads to palpitations and arrhythmias, commonly presenting as premature beats and tachycardia, with characteristic changes visible on electrocardiogram (ECG). As the condition progresses, myocardial contractility decreases, resulting in chest tightness and low blood pressure. In severe cases, ventricular fibrillation or heart failure may be triggered, posing a life-threatening risk.

　　4. Urinary system manifestations: Chronic hypokalemia can damage renal tubular function, impairing the kidney's concentrating ability. This results in polyuria and increased nocturia, with daily urine output reaching over 3,000 mL, accompanied by thirst and frequent drinking. Some patients may have small amounts of protein in their urine, indicating mild kidney injury.

　　5. Signs related to metabolic alkalosis: Hypokalemia is often accompanied by metabolic alkalosis, which may cause tetany of the hands and feet, perioral numbness, and occasional facial muscle twitching. Some individuals may experience restlessness, lethargy, and, in severe cases, confusion.

　　To prevent hypokalemia, it is important to ensure adequate daily potassium intake by consuming potassium-rich foods such as bananas, spinach, and potatoes. After diarrhea or excessive sweating, promptly replenish fluids with diluted saline. Individuals taking diuretics should monitor their blood potassium levels as directed by a physician, have regular electrolyte check-ups, and avoid adjusting medication doses without medical advice.