How are you tested for Hepatitis c?

A simple blood test.

First, Hepatitis C isn't an STD. It's transmitted through blood to blood contact.

You're diagnosed with Hepatitis C after having a blood test taken. If you show up positive for HCV, people are typically recommended to for genotype testing.
Blood tests....
I have had about five or six......so far they have all been negative...
My husband passed away 12 1/2 years ago of hepatitis C induced cirrhosis.....
It was horrible...... I had to be tested while he was sick and every year for three years; and then every other year up till ten years....
If I ever get symptoms I will have to be tested again.
Just a simple bloodtest
It is a simple blood test to detect antibodies to the Hep C virus. The virus is spread through blood and body fluids, so it can be spread through sexual contact, sharing needles, contaminated blood transfusion, etc. Blood banks now routinely check donor units for the virus, so it's unlikely you can get it from a blood transfusion now, but quite a few people were infected before testing commenced.