A
steroid is a biologically active organic compound with four
rings arranged in a specific molecular configuration. Steroids
have two principal biological functions: as important components
of cell membranes which alter membrane fluidity; and as
signaling molecules. Hundreds of steroids are found in plants,
animals, and fungi.
There are many
different steroids, testosterone is one type, it increases
muscle mass and men produce more of it then women. Other types
are progesterone, helps maintain pregnancy among other things.
Prednisone, which reduces inflammation to help people with
breathing problems.
All testosterone is a
steroid, but not every steroid is testosterone.