Celiac disease is an uncommon disease in which your immune system attacks the cells lining the small intestine. Signs and symptoms of celiac disease may include: 1  diarrhea,  bloating,
In humans, disease is often used more broadly to refer to any condition that causes pain, dysfunction, distress, social problems, or death to the person afflicted, or similar problems for those in contact with the person.orbidity (from Latin morbidus, meaning sick, unhealthy) is a diseased state, disability, or poor health due to any cause. The term may be used to refer to the existence of any form of disease, or to the degree that the health condition affects the patient.
Primary bacterial diseases are caused by invasion of bacteria that cause disease with no other predisposing factors. Secondary bacterial diseases are caused by invasion of bacteria after a predisposing condition, such as viral infections, stresses, tissue injuries, and dietary upsets.A bacterial disease may affect a single tissue or organ, or it may affect multiple tissues and organs of the animal.iruses often infect specific types of cells causing damage to the tissues or organs that those cells make up. Similar to bacte-rial disease, viruses can be found in the bloodstream, which is called viremia. Viruses are causative agents of many types of animal diseases.