A disease is a disorder of structure or function in a human, animal, or plant, which produces specific signs or symptoms, and that is not simply a direct result of physical injury. It can impact a specific location or affect the whole organism.

Diseases are typically considered to be medical conditions associated with specific symptoms and signs. They may be caused by external factors, such as infectious agents, or by internal dysfunctions, such as autoimmune disorders.

Here are a few key aspects of what constitutes a disease:

• Abnormal Condition: Departure from normal health.
• Specific Signs/Symptoms: Identifiable indicators.
• Cause: May be infectious, genetic, or environmental.
• Impact: Can affect physical, mental, and/or social well-being.

For more detailed information, you can refer to the following resources:

• World Health Organization (WHO)
• Centers for Disease Control and Prevention (CDC)