Your question affords an opportunity to illustrate the frequently optional nature of article usage in English, and to point out that the search for a dependable and universally applicable "rule" governing the usage of the articles in English is, sadly for the learner, a "fool's errand."
The example sentence you present could actually be written without any articles at all!
Absence of timely treatment of arthritis can worsen symptoms of disease.
As ungainly as this sentence is, it would not be out of place in any issue of Science, Nature, or The Lancet. It is a commonplace in technical and scientific writing to dispense with the articles; this is a matter of style, but there is an underlying purpose which deserves explication, especially to the interested student of English.
In medical literature particularly, the objective seems to be to use the articles only when omitting them creates an irresolvable ambiguity. One reason for this may be the simple desire to reduce the number of words in a given piece of writing. Medical students are required to read an enormous number of words, and reducing that number even by a small percentage provides a tangible benefit. For example, in a favorable review of An American Text-Book of Surgery, (1899), The Medical World, Volume 18, page 110 tells us:
Conciseness is gained by the omission of such articles as "a," "an," and "the," except where necessary.
Another plausible explanation of this phenomenon is that in medicine (and in the sciences generally) many of the nouns are mass nouns: hospital, pain, disease, medicine, treatment, diagnosis, etc., appear frequently as uncountable, e.g.:
In hospital, pain and disease not amenable to treatment and diagnosis are encountered...
Whatever the reason, English technical and scientific writing is littered with nouns unaccompanied by articles. If you are a student of English whose sights are set on a career in medicine, engineering, political science, etc., you should be prepared to see and hear many such usages.