Lesion

A lesion is any damage or unusual change in the tissue of an organism, usually from injury or diseases. The word lesion comes from the Latin word laesio, meaning "injury." Lesions can happen in both plants and animals.

Lesions are important because they help scientists and doctors learn what is wrong when something is not right in the body. By studying lesions, experts can find out about different diseases and how they change living things.

In plants, lesions might look like brown or black spots on leaves, showing the plant is sick or stressed. In animals, including humans, lesions can look like sores, bumps, or other changes on the skin or inside the body.

Learning about lesions helps with treating illnesses and keeping the health of many living things safe. Whether it is a small spot on a leaf or a mark on skin, lesions give important clues about health and disease.

Types

Lesions are changes or damage in body tissues. They can happen anywhere in the body because of injury or disease. Lesions are often grouped by where they occur, their size, or what caused them. For example, lesions in the lungs from tuberculosis are called Ghon lesions. Skin lesions from the varicella zoster virus are known as chickenpox. Damage to teeth is usually called dental caries or cavities.

Lesions can also be named based on their location, such as skin lesions or a brain lesion. If they are caused by a tumor, they may be described as malignant (harmful) or benign (not harmful). The size of a lesion can be seen with the naked eye or only under a microscope. Some lesions take up space and push on nearby tissues, while others do not.

Research using lesions

Brain lesions help scientists learn about how the brain works. When one part of the brain is damaged, it can change some thinking skills but leave others unchanged.

A sham lesion is a test where animals are prepared but not harmed, helping scientists compare results. Scientists study people with brain injuries to understand which parts control specific functions. Sometimes, they use transcranial magnetic stimulation to safely mimic brain damage for tests. With animals, researchers can create lesions in specific areas, such as damaging the hippocampus in rats to study memory.

Notable lesions

Lesions are changes or damage in body tissues caused by injury or disease. They can appear in many different parts of the body and have various names based on where they occur and what they look like.

Some common types of lesions include soft-tissue lesions like the Morel-Lavallee lesion and Bankart lesion, bone lesions such as the Non-ossifying fibroma and Hill–Sachs lesion, and skin lesions like the Melanocytic nevus and Kaposi's sarcoma. There are also lesions linked to specific conditions, such as diabetes-associated lesions like the Armanni-Ebstein lesion, and brain lesions like Olney's lesions. Each type of lesion helps doctors understand and treat health problems.