Hypokalemia

CLINICAL DIAGNOSTIC MANUAL

Hypokalemia is defined as a plasma potassium concentration below 3.5 mmol/L. Potassium is an essential electrolyte for normal cellular function, particularly in muscles and nerves.

A decrease in potassium levels can significantly affect muscle and cardiac function. The causes of hypokalemia are varied and include gastrointestinal losses, renal losses, and intracellular potassium shifts.

Identifying and correcting the underlying cause is crucial for the effective management of this condition.

Pathology	Clinical Symptoms and Signs	Suspected Diagnosis	Confirmatory Diagnosis
Diuretic treatment	Muscle weakness, cramps, fatigue, cardiac arrhythmias	History of diuretic use	Serum potassium measurement, medication review
Beta-agonist treatment	Muscle weakness, palpitations	History of beta-agonist use	Serum potassium measurement, medication review
Vomiting	Muscle weakness, cramps, fatigue	History of frequent vomiting	Serum potassium measurement, evaluation of vomiting cause
Chronic diarrhea	Muscle weakness, cramps, fatigue	History of persistent diarrhea	Serum potassium measurement, evaluation of diarrhea cause
Laxative abuse	Muscle weakness, cramps, fatigue	History of excessive laxative use	Serum potassium measurement, laxative use evaluation
Intestinal fistula	Muscle weakness, cramps, fatigue	History of intestinal fistula	Serum potassium measurement, clinical evaluation of fistula
Villous adenoma of the rectum	Muscle weakness, cramps, fatigue	History of gastrointestinal symptoms	Serum potassium measurement, colonoscopy, biopsy
Primary hyperaldosteronism	Muscle weakness, hypertension, cramps	Resistant hypertension, hypokalemia	Aldosterone and renin measurement, adrenal imaging (CT, MRI)
Renal tubular lesions	Muscle weakness, cramps, fatigue	History of kidney disease, toxin exposure	Serum potassium measurement, renal function tests, clinical history
Recovery phase of renal failure	Muscle weakness, cramps, fatigue	History of recent renal failure	Serum potassium measurement, renal function tests
Recent pyelonephritis	Muscle weakness, cramps, fatigue	History of recent kidney infection	Serum potassium measurement, renal function tests, clinical history
Multiple myeloma	Muscle weakness, cramps, fatigue, bone pain, anemia	History of systemic symptoms, lab tests	Serum potassium measurement, protein electrophoresis, bone marrow biopsy
Heavy metal poisoning	Muscle weakness, cramps, fatigue	History of heavy metal exposure	Serum potassium measurement, specific tests for metal poisoning
Congenital renal tubular defects	Muscle weakness, cramps, fatigue, poor growth in children	Family history, symptoms since childhood	Serum potassium measurement, genetic tests, renal biopsy