CHEM-7 is a group of blood tests that provides information about your body's metabolism. The test is commonly called a basic metabolic panel.

See also:

• Blood chemistry
• CHEM-20

Blood is drawn from a vein, usually from the inside of the elbow or the back of the hand. The site is cleaned with germ-killing medicine (antiseptic). The health care provider wraps an elastic band around the upper arm to apply pressure to the area and make the vein swell with blood.

Next, the health care provider gently inserts a needle into the vein. The blood collects into an airtight vial or tube attached to the needle. The elastic band is removed from your arm.

Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.

In infants or young children, a sharp tool called a lancet may be used to puncture the skin and make it bleed. The blood collects into a small glass tube called a pipette, or onto a slide or test strip. A bandage may be placed over the area if there is any bleeding.

You should not eat or drink for 8 hours before the test.

When the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.

This test can be used to evaluate kidney function, blood acid/base balance, and your levels of blood sugar, and electrolytes. Depending on which lab you use, a CHEM-7 may also check your levels of calcium and a protein called albumin.

• BUN: 7 to 20 mg/dL
• CO2 (carbon dioxide): 20 to 29 mmol/L
• Creatinine: 0.8 to 1.4 mg/dL
• Glucose: 64 to 128 mg/dL
• Serum chloride: 101 to 111 mmol/L
• Serum potassium: 3.7 to 5.2 mEq/L
• Serum sodium: 136 to 144 mEq/L

Key to abbreviations:

• L = liter
• dL = deciliter = 0.1 liter
• mg = milligram
• mmol = millimole
• mEq = milliequivalents

Abnormal results can be due to a variety of different medical conditions, including kidney failure, breathing problems, and diabetes-related complications. See the individual tests for detailed information:

• BUN
• Creatinine
• CO2 (carbon dioxide)
• Glucose
• Serum chloride
• Serum potassium
• Serum sodium

Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.

Other risks associated with having blood drawn are slight but may include:

• Excessive bleeding
• Fainting or feeling light-headed
• Hematoma (blood accumulating under the skin)
• Infection (a slight risk any time the skin is broken)