Sodium (Na) in Blood

Blood Sodium

Results

A sodium test checks how much sodium (an electrolyte and a mineral) is in the blood. Normal values may vary from lab to lab. Results are ready in 1 day.

Sodium

Blood:	136–145 millimoles per litre (mmol/L) or 136–145 milliequivalents per litre (mEq/L)

Many conditions can affect sodium levels. Your doctor will talk with you about any abnormal results that may be related to your symptoms and medical history.

High values

• High sodium levels (hypernatremia) can be caused by a high-sodium diet or by not drinking enough water and being dehydrated. Dehydration may also be caused by severe vomiting or diarrhea, Cushing's syndrome, kidney disease or injury, diabetic ketoacidosis, or a condition called diabetes insipidus that makes it hard to balance the water level in the body.
• High sodium levels can also be caused by high levels of the hormone aldosterone (hyperaldosteronism).

Low values

• Low sodium levels (hyponatremia) can be caused by a lot of sweating, burns, severe vomiting or diarrhea, drinking too much water (psychogenic polydipsia), or poor nutrition.
• Low sodium levels can also be caused by underactive adrenal glands or thyroid gland, heart failure, kidney disease, cirrhosis, cystic fibrosis, or SIADH (syndrome of inappropriate antidiuretic hormone secretion).

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Author:	Jan Nissl, RN, BS	Last Updated: January 10, 2007
Medical Review:	Martin Gabica, MD - Family Medicine Avery L. Seifert, MD - Urology Andrew Swan, MD, CCFP, FCFP - Family Medicine
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