Diagnose   
To determine the cause of an illness or medical condition.

Diagnostic radiologist   
A medical specialist trained to read x-rays.

Diarrhea   
Liquid or watery stool.

Drug resistance   
The result of cancer cells’ ability to resist the effects of a specific drug.

Durable power of attorney   
A legal document that gives a person or persons the authority to make decisions for another person.

Dysphagia   
Difficulty swallowing either solids or liquids.

Dysplasia   
An increase in both the number of cells in a tissue and in the size of those cells, a precancerous change.

Dyspnea   
Difficult or painful breathing; shortness of breath.

Dysuria   
Difficult or painful urination.