The question is incomplete and the full version can be found online.
Answer: He told me that the doctor that has attended him for years can´t explain why he has very bad health even though he lives very carefully.
Step-by-step explanation:
The question requires combining the set of Simple sentences into one Complex sentence.
A complex sentence contains an independent clause (one that can stand alone as a sentence) and at least one dependent clause, which cannot stand alone despite having a subject and a verb. The clauses, then, are not equal, and there has to be a coordinating conjunction that establishes the rank of one or more of the clauses to make them less equal.
In this example, the coordinating conjunctions used are "that" and "even though."