Also known as:Cu; Urine Copper; Blood Copper; Free Copper; Hepatic Copper
Formal name:Copper, 24-hour urine, total and free blood, and liver (hepatic) tissue
Related tests:Ceruloplasmin; Trace Minerals; Heavy Metals
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Why Get Tested?
To measure the amount of copper in the blood, urine, or liver tissue; to help diagnose and monitor Wilson disease; sometimes to identify copper deficiency or excess
When to Get Tested?
When you have jaundice, fatigue, abdominal pain, behavioral changes, tremors, or other symptoms that a health practitioner 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
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?
How is it used?
Copper testing is primarily used to help diagnose Wilson disease, a rare inherited disorder that can lead to excess storage of copper in the liver, brain, and other organs. Less commonly, a copper test may be used to detect copper excess due to another condition, to detect a copper deficiency, or to monitor treatment for one of these conditions.
Copper is an essential mineral but in excess, it can be toxic. In the blood, most of it is incorporated into the enzyme ceruloplasmin and only a small amount is in a "free" or unbound state. (See the "What is being tested?" section for more on this.)
Typically, a total blood copper test is ordered along with a ceruloplasmin level. If the results from these tests are abnormal or unclear, then they may be followed by a 24-hour urine copper test to measure copper elimination and/or a copper test performed on a liver biopsy to evaluate copper storage in the liver.
Sometimes a free (unbound) blood copper test is also ordered. If Wilson disease is suspected, genetic testing may be performed to detect mutations in the ATP7B gene. However, these tests have limited availability and are usually performed in special reference or research laboratories.
Rarely, a copper test may be used to help diagnose Menkes kinky hair syndrome, a rare inherited disorder of copper transport dysfunction. (See Common Questions #4.)
When is it ordered?
One or more copper tests are ordered along with Ceruloplasmin when someone has signs and symptoms that a health practitioner suspects may be due to Wilson disease, excess copper storage, or copper poisoning. These signs and symptoms may include:
- Nausea, abdominal pain
- Behavioral changes
- Difficulty walking and/or swallowing
Testing may be ordered when a person has signs and symptoms that may be due to a copper deficiency, such as:
- Abnormally low numbers of neutrophils, a type of white blood cell (neutropenia)
- Less commonly, neurologic symptoms and delayed growth in children
One or more of the copper tests may be ordered periodically when monitoring is recommended.
A hepatic (liver) copper test may be ordered to further investigate copper storage when copper and ceruloplasmin results are abnormal or equivocal.
What does the test result mean?
Copper test results must be evaluated in context and are usually compared to ceruloplasmin levels. Abnormal copper results are not diagnostic of a specific condition; they indicate the need for further investigation. Interpretation can be complicated by the fact that ceruloplasmin is an acute phase reactant - it may be elevated whenever inflammation or severe infections are present. Both ceruloplasmin and copper are also increased during pregnancy and with estrogen and oral contraceptive use.
Test results may include:
|Test||Wilson Disease||Copper Toxicity||Menkes Disease (Kinky Hair Syndrome)||Copper Deficiency|
|Copper, blood||Low but may be normal||High||Low||Low|
|Copper, serum free||High||High||Low||Low|
|Ceruloplasmin||Low but may be normal||High||Low||Low|
|Copper, urine||Very high||High||Low||Low|
|Copper, liver/hepatic*||Positive but, depending on the site sampled, may be negative||High or normal||Low||Low|
*Excess copper in the liver is often unevenly distributed and may not be detected in a sample.
- Low blood copper concentrations along with increased urine copper levels, low ceruloplasmin levels, and increased hepatic copper are typically seen with Wilson disease.
- Increased blood and urine copper concentrations and normal or increased ceruloplasmin levels may indicate exposure to excess copper or may be associated with conditions that decrease copper excretion, such as chronic liver disease, or that release copper from tissues, such as acute hepatitis. Increased hepatic copper may be present with chronic conditions.
- Decreased blood and urine copper concentrations and decreased ceruloplasmin may indicate a copper deficiency.
- A normal hepatic copper test may indicate that copper metabolism is functioning properly or that the distribution of copper in the liver is uneven and the sample is not representative of the person's condition.
If a person is being treated for Wilson disease or copper toxicity with drugs that bind copper (chelators), then that person's 24-hour urine copper levels may be high until body copper stores decrease. Eventually, blood copper and 24-hour urine copper concentrations should normalize.
If someone is being treated for a condition related to copper deficiency and the person's ceruloplasmin and total copper concentrations begin to rise, then the condition is likely responding to the treatment.
Is there anything else I should know?
Medications such as carbamazepine and phenobarbital can increase blood copper levels. They may also be elevated with rheumatoid arthritis and with some cancers and decreased with a variety of conditions associated with malabsorption, such as cystic fibrosis.
Total serum copper concentrations are normally low at birth, rise over the next few years, peak, and then decline slightly to a relatively stable level.
Care must be taken, especially with a 24-hour urine sample, not to contaminate the sample with an external source of copper. Talk to the health practitioner and/or the laboratory that will perform the test about necessary precautions. If a urine or blood copper test result is higher than expected, the health practitioner may have the test repeated with a new sample to confirm the findings.
What is being tested?
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 production of melanin (the pigment that produces skin color), and the function of the nervous system. This test measures the amount of copper in the blood, urine, or liver (hepatic).
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 food or liquids in the intestines, converts it to a non-toxic form 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 eliminates excess copper into the bile and it is removed from the body in the stool. Some copper is also eliminated in the urine.
Both excess and deficiency of copper are rare. Wilson disease, a rare inherited disorder, can lead to excess storage of copper in the liver, brain, and other organs. Copper excess (toxicity) can also occur when a person is exposed to and absorbs large amounts over a short period of time (acute exposure) or various amounts over a long period (chronic exposure).
Copper deficiency 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.
A rare X-linked genetic condition called Menkes kinky hair syndrome leads to copper deficiency 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 health practitioner 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.
- Should everyone's copper metabolism be evaluated?
General screening for copper concentrations is not recommended or necessary. Many people with conditions not associated with copper, such as people with infections or inflammation, may have temporarily increased concentrations.
- Can I choose either a blood (total or free) or urine copper test?
These tests provide complementary information and your healthcare provider will determine which tests are necessary to evaluate your condition.
- Should I be taking copper supplements or trying to get more copper in my diet?
In most cases, a regular diet satisfies the body's requirements for copper. Talk to your healthcare provider before taking any supplements or changing your diet.
- What is Menkes kinky hair syndrome?
Menkes kinky hair syndrome, also called copper transport disease, is a rare inherited disorder that causes a deficiency in copper. The syndrome is caused by mutations in the ATP7A gene located on the X chromosome. It is passed from parent to child in an X-linked recessive manner. This means that girls must inherit two copies of the mutated gene in order to be affected. Because boys only have one X chromosome, they can be affected if the mutation is present on the one X chromosome.
The mutation leads to uneven distribution of copper in the body. It may build up in tissues of the intestines and kidneys, for example, but may be deficient in areas such as the brain. Symptoms of the syndrome typically develop in infancy and many children die at a young age. Signs and symptoms include sparse, kinky hair, failure to grow at an expected rate and developmental delay, nervous system deterioration, weak muscle tone and seizures. The incidence of this syndrome is about 1 in 100,000 infants.
© 2017 American Association for Clinical Chemistry, republished from Lab Tests Online.*
Descriptions of clinical laboratory tests were originally prepared for use on Lab Tests Online, an award-winning patient education website on clinical laboratory testing. Lab Tests Online is produced by the American Association for Clinical Chemistry (AACC), a global scientific and medical professional organization dedicated to clinical laboratory science and its application to healthcare. The Lab Tests Online website is developed in collaboration with other laboratory professional societies and is funded in part through corporate sponsorships.