I had blood work and I would like to know what it means when doctors say::
Low levels of C5 indicate either increased catabolism or decreased synthesis.
I don't know what catabolism means nor synthesis. Can you please help me?
Also, paperwork had listed C5, Serum--------21   H   mg/dL I appreciate anything you can tell me. I have lupus and a lot of problems, but looking for light at the end of the tunnel. Thank you,Suzanne Gates

Optional Information:
Female , Age: 62

Already Tried:
I'm just waiting to see my doctor again.