Potassium is the major cation inside of cells and helps to create membrane potential, which helps in neurotransmission, heart function, and muscle contraction. Potassium is regulated in renal function.
Normal serum potassium levels range from 3.5 to 5.0 mEq/L. Patients with serum values below 3.5 are hypokalemic and can develop U-waves, weakness, and constipation. Patients with values above 5.0 are considered hyperkalemic and can display weakness, diarrhea, cramping, and arrhythmias with T-waves.
Calcium serves a wide array of functions in the body, working in signal transduction, muscle contraction, neurotransmission, vasodilation, and hormone secretion. The normal range for serum calcium is 8.5-10.5 mg/dL.
The normal range for serum calcium is 8.5-10.5 mg/dL. Hypocalcemic patients can display depression, hallucinations, tingling, and paresthesias, which can further progress to arrhythmias and myocardial infarction. Hypercalcemic patients may develop nausea and vomiting, which can progress to cerebellar ataxia and coma if the condition worsens or is not corrected.
Phosphorous is a key component of DNA and RNA and is used extensively to transport cellular energy in ATP. It mainly exists as a phosphate ion in humans, and the normal serum value of phosphate is between 2.5-4.5 mg/dL.
The normal serum value for serum phosphate is 2.5-4.5 mg/dL. Hypophosphatemia can manifest as muscle and neurological dysfunction as well as disruption of muscle and blood cells due to lack of ATP. Conversely, hyperphosphatemic patients can present with diarrhea and calcification (hardening) of organs. Additionally, soft tissues can show a decreased ability to use iron, calcium, magnesium, and zinc.
The normal serum value for magnesium is 1.5 to 2.5 mEq/L. This electrolyte is important in cellular function and affects cardiovascular function, dreaming, muscle contraction, and insulin regulation.
Normal magnesium serum levels range between 1.5 to 2.5 mEq/L. Patients with hypomagnesemia show muscle weakness, increased reflexes, and tetany, and can develop convulsions. On the other hand, those with hypermagnesemia show bradycardia and flushing at mildly increased levels. As hypermagnesemia increases, patients can present with flaccid paralysis and EKG changes. At magnesium levels above 15, respiratory arrest and asystole occur.
Sodium is a major contributor to cell osmolality and overall body water balance. Sodium is also important in neuroconduction and muscle contraction.
Normal sodium serum values range from 135-145 mEq/L. Patients with hyponatremia show symptoms of lethargy, anorexia, muscle cramping, and nausea. Those with hypernatremia display increased thirst, muscle twitching, hyperreflexia, and seizures. Hypernatremia can also progress to coma.
Chloride is an important anion in the body and is essential to maintaining acid-base homeostasis along with cellular metabolism. Furthermore, chloride plays a role in neuronal firing, as it interacts with GABA transport. Chloride is tightly controlled by the kidney, and the normal serum range is from 95-105 mEq/L.
Normal chloride levels in the serum range from 95-105 mEq/L. Decreased chloride may be seen in patients with metabolic alkalosis, whereas increased chloride levels may be observed in those with respiratory or metabolic acidosis.
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