Lesion

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

Lesions are important because they help scientists and doctors understand what is wrong when something goes wrong in the body. By studying lesions, experts can learn about different diseases and how they affect living things.

In plants, lesions might appear as brown or black spots on leaves, showing that 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.

Understanding lesions helps with treating illnesses and protecting the health of many living organisms. Whether it's 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, and they can happen anywhere in the body due to injury or disease. There isn’t a single way to classify them, but they 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, and 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. Researchers assume that damage to one part of the brain can change certain thinking skills without affecting others, and that the rest of the brain still works normally.

A sham lesion is a control test where animals are prepared for experiments but not actually harmed, helping scientists compare results accurately. Scientists study people with brain injuries to understand which brain parts control specific functions, though it can be hard to find the right patients. Sometimes, they use transcranial magnetic stimulation to temporarily mimic brain damage in safe tests. With animals, researchers can carefully create lesions in specific areas, such as damaging the hippocampus in rats to study memory and recognition.

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 provides important clues for doctors diagnosing and treating various health issues.