You can be infected with the hepatitis C virus and have no symptoms. Your doctor could find it when he checks your blood and sees that your level of certain liver enzymes is high. If that happens, he'll follow up with other tests to confirm you have the disease.
Sharing needles and other equipment (such as cotton, spoons, and water) used to inject drugs.
Having your ears or another body part pierced, getting a tattoo, or having acupuncture with needles that have not been sterilized properly. The risk of getting hepatitis C in these ways is very low.
Working in a health care environment where you are exposed to fresh blood or where you may be pricked with a used needle. Following standard precautions for health care workers makes this risk very low.