Here are Stages of Disease Development
For a disease to develop in your body, it has to undergo some stages. This is part of its nature or rather its natural way of depicting itself. We can therefore avoid getting sick or being infected only if we have enough knowledge of its development.
i.) Stage of Susceptibility
In this stage, the disease has not developed but the ground work has been laid by the presence of factors that favour its occurrence.
In addition, those factors who’s presence is associated with increased probability that disease will develop later are called risk factors.
These factors may be susceptible to change. The risk factors of heart attack may include the following :-
- High blood pressure.
- Family history of heart attack.
- Sex i.e. men are at increased risk.
Moreover, the risk factors that are most important in the community are high blood pressure through treatment and health education to help stop smoking.
ii.) Stage of Presymptomatic Disease
However, at this stage, there is no manifest of disease but usually through interaction of factors, pathogenic changes occur.
The changes are below the level of the clinical horizon.
For example, arteriosclerotic changes in coronary vessels prior to any signs or symptoms of illness.
Risk factors in pregnant women; swollen legs, previous association, High blood pressure, severe anaemia.
iii.) Sub-clinical Stage.
Here basically, there are no signs or symptoms and the person does not know about the presence of any disease.
The infectious agent i.e. bacteria, virus and parasites infects the person without causing any symptoms or signs of disease.
Some adults may have schistosomes (bilharzia) eggs in their urine without having haematuria (blood in urine).
However, the only way of justifying is to do a special test in the laboratory e.g. examining the blood, urine or stool.
The sub-clinical stage of disease may lead to the clinical stage or you may recover without developing any signs and symptoms of the disease. The following diagram shows the stages of Sub-clinical:
iv.) Clinical Stage
Actually in this stage, the person has signs and symptoms of the disease. When the symptoms of the disease become so severe, (you) should go to the hospital.
Here, different diseases will differ in severity and outcome. Diseases such as chickenpox and the common cold have a clinical stage which is short and mild and the patient will recover very quickly.
Diseases like rabies and polio are also very serious. Most people infected from rabies normally die from it. Those with clinical polio will be paralysed.
Outcomes of clinical disease includes: Recovery, Disability and Death.
Therefore, if the disease is severe and no properly treated, the patient may die. Even if he recovers, he may have a disability for the rest of his life such as damaged lung from pulmonary Tuberculosis, amputated legs from severe injury.
Patient who were treated well may recover fully.