At a glance
Also known as
Cu; 24-hour urine copper; total copper; non-caeruloplasmin-bound copper; free copper; hepatic copper; liver copper
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, behavioural changes, tremors or other symptoms that may be due to Wilson’s 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 is collected; sometimes a liver sample
What is being tested?
This test measures the amount of copper in the blood, urine, or liver tissue (hepatic). Copper is an essential mineral that the body incorporates into . These enzymes play a role in the regulation of iron , formation of connective tissue, energy production at the cellular level, the production of melanin (the pigment that produces skin colour), and the function of the nervous system and brain.
Copper is found in many foods including nuts, chocolate, mushrooms, shellfish, whole grains, dried fruits and liver. Drinking water may acquire copper when it flows through copper pipes and food may acquire it when it is cooked or served in copper dishes. Normally, the body absorbs copper from the intestines, makes it non-toxic by binding it to a and transports it to the liver. The liver stores some of the copper and binds most of the rest to a protein called that when copper is attached, becomes the enzyme caeruloplasmin. About 95 per cent of the copper in the blood is bound to caeruloplasmin with the remainder mostly bound to albumin, transcuprein (another copper-binding protein) and copper-amino acid complexes. The liver excretes excess copper into the 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 and such as:
- nausea, abdominal pain
- behavioural changes
- difficulty walking and/or swallowing
Some of these symptoms may also be seen with copper poisoning that is due to or environmental exposure to copper or conditions such as liver disease or obstructions that prevent or inhibit copper metabolism and excretion.
Copper deficiencies may occasionally occur in patients who have conditions associated with severe malabsorption, such as cystic fibrosis and coeliac disease and in infants exclusively fed cow-milk formulas. Manifestations may include , osteoporosis and anaemia. A rare genetic condition called Menke's disease 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 is collected. Sometimes a doctor performs a liver .
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 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. It is up to you and your doctor to determine which tests are necessary to evaluate your condition.
What happens if I am exposed to toxic amounts of copper?
Copper poisoning can cause vomiting and diarrhoea and, in some cases lead to liver and kidney damage. You should talk to your doctor if you think that you have been exposed.
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 doctor before taking any supplements or changing your diet.