Blood Chemistry (Chem, SMAC, electrolytes)

These tests measure the amount of certain chemical substances dissolved in the blood. The exact chemicals tested vary by lab and depends on what exactly your doctor orders.

The most common ones are:

Glucose is the amount of sugar in your blood. Normal values range from 65-115 mg/dl but may be higher just after eating. Certain medications such as steroids can increase your glucose level.

Blood Urea Nitrogen (BUN)
BUN is produced by the liver and excreted through the kidneys. The normal level is 7-25 mg/dl. An elevated level may indicate improperly functioning kidneys.

Creatinine is also filtered out through the kidneys. An elevated level can indicate kidney problems. The normal value is less than 1.5mg/dl.

Sodium (Na), Potassium (K), Chloride
These minerals are present in the blood at all times. They must be present in the right amounts in order for the body’s “electrical system” to work properly. This electricity is needed for all cells to work normally.

Keeping these minerals at the proper levels is the job of the gastrointestinal tract, the kidneys, and the lungs. An abnormal reading usually indicates a problem in one of these
areas or dehydration.

The normal levels are:
Potassium- 3.5 – 5.4
Sodium- 135 – 147 MEQ/L
Chloride- 96-109 MEQ/L

For more information:

Central – Lab Tests, What They Mean
to review your blood test results

Yale University School of Medicine, Patient’s Guide to Medical Tests