Disease/dɪˈziːz/ Definition 1 of 3Pro Tip 1/3Physical Ailment Refers to actual illnesses or disorders affecting the body or mind, not metaphorical issues. Malaria is a disease spread by mosquitoes. Pro Tip 2/3Medical Context Most often used in healthcare and medicine to discuss symptoms and treatments. The doctor specialized in tropical diseases. Pro Tip 3/3Severity and Duration Can imply chronic or acute conditions; some diseases can be lifelong, others temporary. Diabetes is a chronic disease with various treatment options.