Serum or Plasma Sodium Concentration (Electrolyte Profile)

Why This Test Matters

Sodium is a key electrolyte that helps regulate how fluids move in and out of your cells. Low or high sodium levels can cause serious health issues, such as confusion, muscle weakness, or even heart problems. Your doctor may order this test if you have symptoms like excessive thirst, swelling, or irregular heartbeat, or if you’re taking certain medications that affect sodium balance.

What to Expect Before the Test

You can eat and drink normally before this test. If you’re having blood drawn, tell your healthcare provider about any medications you’re taking, as some can affect sodium levels. Avoid heavy exercise or dehydration before the test.

What the Results Mean

Results are usually reported as a concentration in milliequivalents per liter (mEq/L). Your doctor will compare these results to your typical range and your symptoms to determine if further action is needed.

Common Causes of Abnormal Results

Low sodium levels (hyponatremia) can occur from excessive sweating, vomiting, diarrhea, or certain medications. High sodium levels (hypernatremia) may be linked to dehydration, kidney problems, or overuse of salt.