What is a Disease?
When it comes to defining a disease, there is no one completely satisfying definition. That’s because there are thousands of different types of diseases, each with its own subtypes.
A disease is a broad term for any medical condition that negatively affects the functioning or the structural features of the body that is associated with signs and symptoms.
Some important terms:
It is the study of diseases based on the extent, occurrence, distribution and control in the population.
It is important to keep a statistical record and surveillance on a disease in order to successfully study its nature and prepare for the disaster in order to prevent negative health outcomes and improve global health in the long term.
Endemic – Disease that is regularly found in the population. For example, Tuberculosis.
Epidemic – This term is used for diseases that spread rapidly in a community. For example, Plague.
Pandemic – A term for diseases that spreads globally, worldwide. For example, Coronavirus.
Diseases and Immunity
When a disease occurs and symptoms start to show, it usually means that the invading harmful body has overpowered the immune system’s ability or is a result of interaction between immune cells and the bacteria. The immune system in our body is a complex system that protects us from external factors.
Although we may not realize it, we come in contact with germs and bacteria in our daily life. Simple daily activities like gardening, petting your dog or even touching other people or your environment could transfer bacteria and germs into your body.
This is why we need a strong immune system as our body needs to continuously fight off infections.
The immune cells consist of white blood cells like lymphocytes (T cells and B cells) , neutrophils and macrophages. Their sole purpose is to signal cytokinesis, antibodies and other complex proteins to fight off invading foreign bodies.
Thus, the main job of the immune system is to detect and differentiate between your own body cells and the harmful foreign cells of substances like the bacteria or viruses.
Classification of Diseases
There are many ways to classify diseases based on their cause, mode of action, symptoms or their target organs or cell.
In general, they are mainly classified into the following:
Degenerative diseases – It is the gradual decline of a specific function in the body that worsens over time and may lead to a complete shutdown of the organ or system. Eg. Cardiovascular, skeletal, muscular or neuro disease.
Infectious diseases – This disease is caused when pathogens like bacteria, viruses, parasites or fungi enter the body and begin to multiply. They can usually be transmitted from person to person and are termed as communicable diseases. Eg. Chickenpox, malaria, HIV etc.
Credits : foter Caption: infectious disease caused by pathogens.
Non-infectious – Any type of disease that is not caused due to pathogens. They usually cannot be transmitted from person to person and are termed as non-communicable disease. Eg. Cancer, heart disease, Alzheimer’s.
Deficiencies – Intake of nutrients is very important for the proper functioning of the body. Deficiency disease is caused by an unbalanced diet or lack of nutrition in the diet leading to various types of symptoms and health deterioration. Eg. Hypocalcemia, haemorrhage, Scruvy.
Hereditary diseases – Genes present in chromosomes are responsible for passing a trait from one generation to the other. This disease is caused when a faulty allele of genes is passed on from parent to child. Eg. Haemophilia, Sickle cell anaemia and Down syndrome.
Physiological diseases – Any disease that affects the physical state of a person and potentially alters their thoughts. It is usually due to the degeneration of brain tissues by environmental factors. Eg. Alzheimer’s, dementia, schizophrenia etc.
It is worth pointing out that one form of a disease could lead to another and some diseases overlap in terms of the category they belong to.
Deficiency disease of vitamin D leading to hypocalcemia could cause a degenerative bone disease, where bones start to break down.
HIV is an infectious as well as a degenerative disease.
Alzheimer’s can be a hereditary, non-infectious and physiological disease.
Most sexually transmitted diseases are infectious diseases that could lead to a degenerative disease. For example, Hepatitis B is caused by a virus and it damages the liver which could potentially lead to liver failure without treatment.
About This Section
On our website, you’ll find comprehensive information about common types of diseases including:
Mental Health Disorders
Diseases specific to women
Pain related illnesses
…. and so on
This section, on the other hand will be dedicated to everything else including (but not limited to):
Certain physiological diseases
Rare diseases such as Morgellons and Fields’ disease