Disorders of blood chemistry may be caused by dietary factors, underlying medical conditions, and medical treatments. Resulting imbalances include acidosis (pH <7.35), alkalosis (pH >7.45), and high or low levels of key electrolyte ions, including sodium (Na), potassium (K), calcium (Ca), magnesium (Mg), chloride (Cl), hydrogen phosphate (HPO4), and hydrogen carbonate (HCO3). They may be acute or chronic, may occur with varying degrees of severity, and may not be sufficiently counteracted by the body's regulatory/compensatory mechanisms.
Electrolyte balance is normally regulated by the hypothalamus, kidneys, and various hormones, including antidiuretic hormone (ADH), aldosterone (a mineralocorticoid hormone), and parathyroid hormone (PTH). Acid-base balance is linked to fluid and electrolyte balance, and is normally controlled and maintained by immediate buffer systems via the kidneys and the pulmonary system. Respiratory acidosis and alkalosis are accompanied by compensatory renal bicarbonate retention and loss, respectively; metabolic acidosis and alkalosis are accompanied by compensatory hyperventilation and hypoventilation, respectively. Mixed metabolic disorders can occur (e.g., diabetic ketoacidosis complicated by vomiting), and evaluation depends on clinical history and examination, assessment of anion gap, serum electrolytes, and arterial blood gases.