Two clear examples of medical suffixes that are also indepenedent medical terms are "-genesis" and "-gram". It is necessary to clear up one technicality in terminology first, though.
"Suffixes" that have Greek or Latin roots and that are used to combine with other words or parts of words are not called "suffixes." These kind of affixes [prefixes and suffixes are both affixes] are correctly called "combining forms." Combining forms are forms of Greek and Latin words that combine with other words or parts of words to form new Hellenic (Greek-based) or Latinate words that are often used in medical vocabulary.
One combining form (suffix) is -genesis.
As an independent medical term, "genesis" means the origin of something. In medicine, a doctor might speak of the genesis of a contagion when speaking of the starting point or point of origin of a contagion.
As a combining form (suffix), -genesis indicates the origin of a particular disease, pathogen or process, for example, "parthenogenesis," which is a single-sex reproductive process (life origin) (Kernerman Webster's and American Heritage Dictionaries).
Another combining form (suffix) is -gram.
As an independent medical term, "gram" indicates the metric weight of something as a unit of mass. Nurses might speak of how much something, like a serving of food, weighs in grams.
As a combining form (suffix), -gram signifies something written down, plotted (on a graph) or drawn, for example a "pictogram" (Kernerman Webster's College Dictionary).