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Also known as: Cu; 24-hour urine copper; Total copper; Non-ceruloplasmin-bound copper; Free copper; Hepatic copper
Formal name: Copper (24-hour urine, total and free blood, and hepatic)
Related tests: Ceruloplasmin; Heavy Metals

At a Glance

Why Get Tested?

To measure the amount of copper in the blood, urine, or liver; to help diagnose and monitor Wilson disease; sometimes to identify copper deficiencies and excesses

When to Get Tested?

When you have jaundice, fatigue, abdominal pain, behavioral changes, tremors, or other symptoms that your doctor thinks may be due to Wilson disease or, rarely, to copper deficiency or excess; at intervals when you are being treated for a copper-related condition

Sample Required?

A blood sample drawn from a vein in your arm and/or a 24-hour urine sample; sometimes a liver biopsy sample

Test Preparation Needed?


The Test Sample

What is being tested?

This test measures the amount of copper in the blood, urine, or liver (hepatic). Copper is an essential mineral that the body incorporates into enzymes. These enzymes play a role in the regulation of iron metabolism, formation of connective tissue, energy production at the cellular level, the creation of melanin (the pigment that produces skin color), and the function of the nervous system.

Copper is found in many foods including nuts, chocolate, mushrooms, shellfish, whole grains, dried fruits, and liver. Drinking water may acquire copper as it flows through copper pipes, and food may acquire it when people cook or serve food in copper dishes. Normally, the body absorbs copper from the intestines, makes it nontoxic by binding it to a protein, and transports it to the liver. The liver stores some of the copper and binds most of the rest to another protein called apoceruloplasmin to produce the enzyme ceruloplasmin. About 95% of the copper in the blood is bound to ceruloplasmin, and most of the rest is bound to other proteins such as albumin. Only a small amount is normally present in the blood in a free (unbound) state. The liver excretes excess copper into the bile and it is removed from the body in the stool. Some copper is also excreted in the urine.

Both excesses and deficiencies of copper are rare. Wilson disease, an inherited disorder, can lead to excess storage of copper in the liver, brain, and other organs. This can cause tissue damage and signs and symptoms such as:

  • Anemia 
  • Nausea, abdominal pain 
  • Jaundice 
  • Fatigue 
  • Behavioral changes 
  • Tremors 
  • Difficulty walking and/or swallowing 
  • Dystonia

If the kidneys are involved, then urine production may be decreased or absent. Some of these symptoms may also be seen with copper poisoning that is due to acute or chronic environmental exposure to copper or due to conditions such as liver disease or obstructions that prevent or inhibit copper metabolism and excretion.

Copper deficiencies may occasionally occur in people who have conditions associated with severe malabsorption, such as cystic fibrosis and celiac disease, and in infants exclusively fed cow-milk formulas. Symptoms may include neutropenia, osteoporosis, and microcytic anemia. A rare X-linked genetic condition called Menkes kinky hair syndrome leads to copper deficiencies in the brain and liver of affected infants. The disease, which affects primarily males, is associated with seizures, delayed development, abnormal artery development in the brain, and unusual gray brittle kinky hair.

How is the sample collected for testing?

A blood sample is obtained by inserting a needle into a vein in the arm and/or a 24-hour urine sample is collected. Sometimes a doctor performs a liver biopsy.

NOTE: If undergoing medical tests makes you or someone you care for anxious, embarrassed, or even difficult to manage, you might consider reading one or more of the following articles: Coping with Test Pain, Discomfort, and Anxiety, Tips on Blood Testing, Tips to Help Children through Their Medical Tests, and Tips to Help the Elderly through Their Medical Tests.

Another article, Follow That Sample, provides a glimpse at the collection and processing of a blood sample and throat culture.

Is any test preparation needed to ensure the quality of the sample?

No test preparation is needed.

The Test

Common Questions

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Article Sources

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NOTE: This article is based on research that utilizes the sources cited here as well as the collective experience of the Lab Tests Online Editorial Review Board. This article is periodically reviewed by the Editorial Board and may be updated as a result of the review. Any new sources cited will be added to the list and distinguished from the original sources used.

Sources Used in Current Review

Greco, F. (Updated 2009 January 20). 24-hour urine copper test. MedlinePlus Medical Encyclopedia [On-line information]. Available online at Accessed December 2010.

McMillin, G. and Roberts, W. (Updated 2010 May). Wilson Disease. ARUP Consult [On-line information]. Available online at through Accessed November 2010.

Haldeman-Englert, C. (Updated 2010 September 10). Wilson's disease. MedlinePlus Medical Encyclopedia [On-line information]. Available online at Accessed November 2010.

Johnson, L. (Revised 2008 August). Copper. Merck Manual for Healthcare Professionals [On-line information]. Available online at disease&alt=sh#sec01-ch005-ch005c-534 through Accessed November 2010.

McMillin, G. et. al. (2009 August 25). Direct Measurement of Free Copper in Serum or Plasma Ultrafiltrate. Medscape Today from American Journal of Clinical Pathology. 2009;131(2):160-165. [On-line information]. Available online at through Accessed November 2010.

Kaler, S. (Updated 2009 May 28). Menkes Kinky Hair Disease. eMedicine [On-line information]. Available online at through Accessed November 2010.

(© 1995-2010). Unit Code 8612: Copper, Serum. Mayo Clinic, Mayo Medical Laboratories [On-line information]. Available online at through Accessed November 2010.

Wu, A. (© 2006). Tietz Clinical Guide to Laboratory Tests, 4th Edition: Saunders Elsevier, St. Louis, MO. Pp 292-295.

Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. Burtis CA, Ashwood ER, Bruns DE, eds. St. Louis: Elsevier Saunders; 2006, Pp 556-559, 1126-1130, 1378-1379.

Sources Used in Previous Reviews

Clarke, W. and Dufour, D. R., Editors (2006). Contemporary Practice in Clinical Chemistry. AACC Press, Washington, DC. Bankson, D. Chapter 35, Vitamins and Trace Elements: Assessment of Micronutrient Status through Laboratory Testing. Pp. 399 410.

Wu, A. (2006). Tietz Clinical Guide to Laboratory Tests, Fourth Edition. Saunders Elsevier, St. Louis, Missouri. Pp. 292-295.

Alexander, D. (2006 March 2, Updated). 24-hour urine Copper/Cu. MedlinePlus Medical Encyclopedia [On-line information].  Available online at Accessed 7/21/07.

McGee, W. (2007 March 2, Updated). Copper in diet. MedlinePlus Medical Encyclopedia [On-line information]. Available online at Accessed 7/25/07.

Perez, E. (2006 October 23, Updated). Copper poisoning. MedlinePlus Medical Encyclopedia [On-line information]. Available online at Accessed 7/25/07.

(2004). Copper. ATSDR Division of Toxicology ToxFAQs [On-line information]. Available online at through Accessed 7/25/07.

(2007 February 13, Updated). Menkes Disease Information Page. NINDS [On-line information]. Available online at through Accessed 7/25/07.

(2007 February 14). Zellweger Syndrome Information Page. NINDS [On-line information]. Available online at through Accessed 7/25/07.

Thomas, Clayton L., Editor (1997). Tabers Cyclopedic Medical Dictionary. F.A. Davis Company, Philadelphia, PA [18th Edition]. Pp. 441.

Copper. Merck Manual of Medical Information Second Home Edition [On-line information]. Available online at through Accessed 7/17/07.

Das, S. and Ray, K. (2006 October 13). Wilsons Disease: An Update. Medscape from Nature Clinical Practice Neurology [On-line information]. Available online at through Accessed 7/27/07.

Turnlund, J. (2007 July, Reviewed). Copper. Linus Pauling Institute Micronutrient Research for Optimum Health, Micronutrient Information Center, Oregon State University [On-line information]. Available online at through Accessed 9/16/07.

(2006 August 1). Copper. MedlinePlus Health Information, Herbs and Supplements [On-line information]. Previously available online at Accessed 9/16/07.

Barnes, N. et. al. (2005). The copper-transporting ATPases, menkes and wilson disease proteins, have distinct roles in adult and developing cerebellum. Medscape from J Biol Chem. 2005; 280(10): 9640-5 (ISSN: 0021-9258) [On-line abstract]. Available online at through Accessed 9/16/07.

Shim, H. and Harris, Z. L. (2003 May). Supplement: 11th International Symposium on Trace Elements in Man and Animals, Genetic Defects in Copper Metabolism. J. Nutr. 133: 1527S-1531S [On-line journal article]. Available online at through Accessed 9/16/07.

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