Which one of the following diseases is a communicable?
**Core Concept**
Communicable diseases, also known as infectious diseases, are conditions caused by pathogens such as bacteria, viruses, fungi, or parasites that can be transmitted from one person to another. These diseases can spread through direct or indirect contact, airborne transmission, or vectors like insects.
**Why the Correct Answer is Right**
A communicable disease is characterized by its ability to be transmitted between individuals. This is often due to the presence of a pathogen in the host, which can be shed into the environment and infect others. For example, the measles virus is a highly communicable pathogen that spreads through respiratory droplets, leading to widespread outbreaks. In contrast, non-communicable diseases like diabetes or hypertension are not caused by pathogens and do not spread from person to person.
**Why Each Wrong Option is Incorrect**
**Option A:** Diabetes mellitus is a chronic metabolic disorder caused by insulin resistance or deficiency, and is not communicable.
**Option B:** Hypertension is a cardiovascular condition characterized by high blood pressure, and is not caused by a transmissible pathogen.
**Option C:** Cancer is a group of diseases characterized by uncontrolled cell growth, and is not typically communicable.
**Clinical Pearl / High-Yield Fact**
It's essential to differentiate between communicable and non-communicable diseases when assessing a patient's risk factors and developing a treatment plan.
**Correct Answer: C. Cancer is a group of diseases characterized by uncontrolled cell growth, and is not typically communicable.**