What is disease?

Disease is a disorder of structure or function in a living organism that results from infection, genetic defects, physical injury, nutritional deficiencies, or chemicals. Diseases are often classified into infectious and non-infectious.

Infectious diseases are caused by microorganisms such as bacteria, viruses, fungi, or parasites. These microorganisms can enter the body through the air, water, food, or contact with infected people or animals. Examples of infectious diseases include the common cold, influenza, measles, mumps, rubella, pneumonia, tuberculosis, sexually transmitted infections, and malaria.

Non-infectious diseases are not caused by microorganisms. They can be caused by a variety of factors, including genetic defects, physical injury, nutritional deficiencies, or chemicals. Examples of non-infectious diseases include cancer, heart disease, stroke, diabetes, chronic kidney disease, and arthritis.

Disease symptoms are the physical or mental changes that occur as a result of a disease. Symptoms can vary depending on the type of disease and the individual person. Some common symptoms include fever, chills, fatigue, pain, swelling, redness, and discharge.

Disease treatment depends on the type of disease and the severity of the symptoms. Treatment options may include medication, surgery, radiation therapy, chemotherapy, or lifestyle changes.

Disease prevention is the practice of taking steps to reduce the risk of developing a disease. Prevention strategies can include vaccination, hand washing, avoiding contact with infected people or animals, eating a healthy diet, and getting regular exercise.