A disease is a condition of the body caused by the effects of excessive or unusual stimuli. A disease causes a deviation from the normal life of the organism, accompanied by structural and functional changes. Diseases can be contagious or non-contagious and can be caused by infection, injury, genetics, environmental or lifestyle factors.
An infection, on the other hand, is a contagion of the body tissues. The body is infected when microorganisms attack and reproduce inside the body, thus causing harm. It is caused by pathogenic microorganisms, their multiplication in cells and the body’s specific immune response to these microorganisms and the toxins produced by them. A microorganism is infectious when it has the ability to cause an infection. Infections can be caused by viruses, bacteria, fungi, and macroparasites such as worms or ticks.
An infection occurs as the result of the body’s immune response to a pathogen. When a pathogen, such as a virus, bacteria, or fungus, enters into the body of a host and begins to multiply or replicate inside it and causes harm, it is called an infection. An infection may cause symptoms and be clinically visible or they may cause no symptoms and be subclinical.
A disease occurs when the body’s immune system is weakened by the pathogen and it starts harming the cells of the body, particularly the area it has infected. They can be communicable, infectious, or noncommunicable. A communicable disease is when the disease transfers from one organism to another. An infectious disease is caused by an infectious agent (bacteria, viruses, fungus, and parasites) living and replicating in its host cell. An infectious disease is communicable too. A non-communicable disease is referred to as a chronic disease, as they progress slowly and last for a longer period. They are mainly caused by genetics, abnormalities since birth, or some environmental conditions.
There are differences in symptoms between an infection and a disease. The symptoms of a disease largely depend on the kind of pathogen that has attacked the body and also the place where it infected the body. Common symptoms of diseases are pain, nausea, vomiting, diarrhoea, swelling, breathing problems, and bleeding. Symptoms of infection may include flu-like symptoms such as a headache, stomach ache, muscle and joint pain, fever, chills, sweating, loss of hunger, runny nose, cough and dizziness. It may also include a swollen and painful wound at the site of infection, and the appearance of pus.
The transmissibility between the two is also different. Diseases can be contagious or non-contagious whereas infections are contagious and can be transferred from an infected person to a healthy person.
The treatment for a disease and an infection depends on what type it is. If properly diagnosed, treating infections can help prevent it from spreading and causing a disease. In terms of treating diseases, there are many different kinds of treatments available for different diseases. Proper medication and surgery are common treatment options. Preventing infections and diseases, such as by maintaining a proper diet, vaccination, and taking self-care measures is a good idea.