Hypokalemia Clinical Presentation

Updated: Dec 29, 2016
  • Author: Eleanor Lederer, MD, FASN; Chief Editor: Vecihi Batuman, MD, FASN  more...
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Presentation

History

The symptoms of hypokalemia are nonspecific and predominantly are related to muscular or cardiac function. Weakness and fatigue are the most common complaints. The muscular weakness that occurs with hypokalemia can manifest in protean ways (eg, dyspnea, constipation or abdominal distention, exercise intolerance). Rarely, muscle weakness progresses to frank paralysis. With severe hypokalemia or total body potassium deficits, muscle cramps and pain can occur with rhabdomyolysis.

Occasionally, a patient may complain of worsening diabetes control or polyuria due to a recent onset of hyperglycemia or nephrogenic diabetes insipidus. Patients also may complain of palpitations. Psychological symptoms may include psychosis, delirium, hallucinations, and depression.

Patients are often asymptomatic, particularly with mild hypokalemia. Symptoms that are present are often from the underlying cause of the hypokalemia rather than the hypokalemia itself.

When the diagnosis of hypokalemia is discovered, investigate potential pathophysiologic mechanisms.

Poor intake may result from the following:

  • Eating disorders
  • Dental problems
  • Poverty

Increased excretion may be due to the following:

  • Medications (eg, diuretics, antiretroviral agents, antibiotics; see Etiology)
  • Polyuria
  • Vomiting or diarrhea

Shift of potassium into the intracellular space may occur due to the following:

  • Recurrent episodes of paralysis
  • Use of high doses of insulin
  • High-dose beta-agonist therapy (eg, for chronic obstructive pulmonary disease)

Ask whether the patient has had similar episodes in the past. Familial historical data may include surgery for pituitary or adrenal tumors or acute intermittent episodes of paralysis, with or without association with hyperthyroidism.

Next:

Physical Examination

Physical examination findings are often within the reference range. Vital signs generally are normal, except for occasional tachycardia with irregular beats or tachypnea resulting from respiratory muscle weakness. Hypertension may be a clue to primary hyperaldosteronism, renal artery stenosis, licorice ingestion, or the more unusual forms of genetically transmitted hypertensive syndromes, such as congenital adrenal hyperplasia, glucocorticoid-remediable hypertension, or Liddle syndrome.

Relative hypotension should suggest occult laxative use, diuretic use, bulimia, or one of the unusual tubular disorders, such as Bartter syndrome or Gitelman syndrome. Bear in mind that occult diuretic use is far more common than either of those congenital tubular disorders and is, in fact, also called "pseudo-Bartter syndrome."

Muscle weakness and flaccid paralysis may be present. Patients may have depressed or absent deep-tendon reflexes. Hypoactive bowel sounds may suggest hypokalemic gastric hypomotility or ileus.

Severe hypokalemia may manifest as bradycardia with cardiovascular collapse. Cardiac arrhythmias and acute respiratory failure from muscle paralysis are life-threatening complications that require immediate diagnosis.

Tooth erosion may be present in patients with bulimia. This finding has particular significance in patients whose history indicates high risk (eg, obsession with body image or participation in activities such as cheerleading, wrestling, or modeling).

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