What are the clinical manifestations of hypokalemia

Hypokalemia refers to a condition in which the body's serum potassium concentration is lower than normal, which is more common in some populations. The clinical manifestations of hypokalemia are presented in many aspects, and different systems may also show different symptoms. For example, patients with neuromuscular system problems are most likely to experience muscle weakness, which means numbness in the limbs.

1. Neuromuscular system

Common symptoms include muscle weakness and paroxysmal flaccid paralysis, which are more common at night and after fatigue. The limbs are most commonly affected, while the muscles of the head and neck are generally not affected. However, the respiratory muscles may be affected, causing dyspnea. Before the onset of the disease, there may be numbness in the limbs, followed by fatigue, and finally the complete disappearance of autonomous activity. Generally, the symptoms of proximal muscles are slightly milder than those of distal muscles. Patients cannot stand, walk, sit or squat and cannot stand up.

2. Cardiovascular system

Low potassium can reduce myocardial excitability and cause various arrhythmias and conduction blocks. Mild cases include sinus tachycardia, atrial or ventricular premature contractions, and atrioventricular conduction block; severe cases include paroxysmal atrial or ventricular tachycardia and even ventricular fibrillation. Potassium deficiency can aggravate digitalis and antimony poisoning and may lead to death.

3. Urinary system

Long-term hypokalemia can damage the renal tubules and cause potassium-deficient nephropathy. The renal tubular concentration, ammonia synthesis, hydrogen secretion and chloride ion reabsorption functions can all be reduced or enhanced. The sodium excretion function or sodium reabsorption function can also be reduced, leading to metabolic hypokalemia and hypochlorite alkali poisoning.

4. Endocrine and metabolic system

Hypokalemia may cause impaired glucose tolerance, and children with long-term potassium deficiency may have delayed growth and development; urinary potassium excretion is reduced (<30mmol/24h), but in cases caused by renal tubular acidosis and acute renal failure, urinary potassium excretion is increased (>40mmol/24h).