Life is a terminal, degenerative, sexually transmitted condition. You, the reader have this condition.
All living things will die.
Degenerative
Living things are subject to various kinds of wear-and-tear which results in deterioration over time.
Sexually transmitted
Sexual reproduction is widespread in the domain of life. An asexually reproducing organism could be said to have a “terminal degenerative condition” instead.
Condition
Life is a condition, not a disease. While “disease” is the usual word partner for “terminal”, a “terminal condition” is also valid.