What Are the Main Causes of Diseases? Types, Factors & Examples
A disease is a condition that worsens or impairs the normal conditions of organisms. Do you know most people die because of heart disease? And most heart diseases are due to a sedentary lifestyle. These factors are modifiable. Do you know the types of diseases? There are acute and chronic diseases. Acute diseases affect us for a short period, whereas chronic disease affects us for a long period.
There are various causes of disease, such as pathogens or unhealthy lifestyles. You might be surprised to know that fever is not a disease, it is a protective mechanism of the body against pathogens.
Types of Diseases
Diseases are of various types based on their nature.
Infectious diseases, also known as communicable diseases
Non-infectious diseases, also known as non-communicable diseases
Degenerative diseases
Allergies
Deficiency diseases
Infectious Diseases
Infectious diseases are diseases that spread from one person to another person through some agent. These diseases are caused by microorganisms such as bacteria, viruses, worms, and protozoans. Examples of infectious diseases are the common cold, pneumonia, tuberculosis, etc.
Non-Infectious Diseases
These are diseases that do not transmit from one person to another. These diseases may be caused by some pathogens or factors such as gender, lifestyle, and nutritional deficiency. Examples are hypertension, diabetes, cancer, asthma, etc.
Degenerative Diseases
Degenerative diseases are diseases caused by degenerative changes in cells, tissues, and organs. Examples of degenerative diseases are Alzheimer's disease and osteoporosis.
Allergies
Allergy is a hypersensitivity type reaction caused because of some substances. Things that cause allergic reactions are called allergens. Dust, mites, pollen, latex, and animal dander are allergens.
Deficiency Diseases
Deficiency diseases are diseases caused due to a decreasing or less amount of hormones, minerals, nutrients, and vitamins in the body. For example, diabetes occurs due to a deficiency of insulin in the blood. Insulin is the hormone produced by the pancreas and converts glucose into glycogen in the liver.
Kwashiorkor or Marasmus are diseases caused due to protein-energy malnutrition, goiter is the disease caused by the deficiency of thyroid hormone.
How are Diseases Caused?
There are various types of causes. Some of the causes are given below:
Airborne Diseases - These are diseases caused by pathogens and transmitted through the air. Examples of these diseases are tuberculosis and the common cold.
Foodborne Diseases - These are the diseases caused by contaminated food and drinks with pathogens, toxins, and parasites. Examples of these diseases are food poisoning.
Lifestyle Diseases - These diseases are caused by a sedentary lifestyle or consumption of unhealthy food or a bad lifestyle. The frequency of these diseases increases with time, especially in developed countries.
Communicable Diseases - These diseases are caused by various pathogens. Pathogens include:
Bacteria - Microscopic organisms that cause various types of diseases such as Streptococcus, Mycobacterium, etc.
Virus - Viral diseases are the common cold, hepatitis, mumps, influenza, and measles. These diseases are caused by rhinovirus, paramyxovirus, etc.
Fungus - Fungal infections include athlete's foot, and toenail fungus, fungal infections mostly occur in warm and humid places.
Protozoa - Protozoan infections include dysentery, amoebiasis, malaria, etc. Protozoans are Entamoeba histolytica and Plasmodium.
Worms - Disease causing worms are guinea worm, giardiasis, etc.
Symptoms of Diseases
Symptoms change according to the nature of the disease. But some of the signs and symptoms are very common and occur in almost every disease. Some of these symptoms are:
Headache
Pain
Vomiting
Nausea
Nasal congestion
Diarrhea
Altered urination
Redness
Swelling or edema
Sore throat
Chills or sweat
Treatment of Diseases
Treatment of diseases also depends on the nature and causative agent.
Antibiotics are drugs used for the treatment of bacterial diseases and infections. Examples of antibiotics are amikacin, penicillin, streptomycin, etc.
Antivirals are used for the treatment of viral diseases. Examples of antiviral drugs are peramivir and oseltamivir.
Antihypertensive drugs are calcium Channel blockers, diuretics, ace inhibitors, beta-blockers, etc.
There are other medications, too given according to diseased conditions.
Preventions of Diseases
It is well said that prevention is better than cure. So to save ourselves from diseases we have to follow certain healthy practices and protective measures. Some of the healthy habits are given below:
Wash hands regularly.
Always eat cooked food.
Exercise daily.
Say no to smoking and alcohol.
Eat less junk food.
Drink more water.
Interesting Facts
Laron syndrome is a disease in which the life span of a patient gets increased, and immunity against cancer develops.
In 5000 years of human history, humans are only able to eradicate two diseases till now - smallpox and rinderpest.
The lack of a toilet in India causes a loss of more than 50 billion dollars per year because of premature deaths and hygiene-related issues.
There was a man named James Harrison whose blood contain a rare antigen that can cure rhesus disease.
Approximately, 90-95% of cases of cancer are due to environmental conditions.
Important Questions
Q1. What are the most common infectious diseases?
Ans: There are many types of infectious diseases. But the most commonly occurring diseases are - influenza, pneumonia, Staphylococcus aureus infection, E.coli infection, etc.
Q2. What are some deadliest diseases?
Ans: There are many deadliest diseases. Some of the deadliest diseases are given below:
Cancer, heart diseases such as heart attack, HIV, and aids. Some of the diseases do not have any treatment.
Q3. What are the rarest diseases?
Ans: Rarest diseases are the diseases that occur very rarely such as alkaptonuria, encephalitis, Alice In Wonderland Syndrome ( AIWS), and Stoneman syndrome.
Key Features
In this article, we discussed disease and what causes disease, causes and prevention of communicable diseases.
There are various types of diseases, such as infectious, non-infectious, degenerative diseases, etc.
Causes of diseases are various pathogens such as bacteria, viruses, and fungus some lifestyle factors also cause disease.
Practice Questions
Q1. What is black urine disease?
Q2. What is the most common disease in the world?
Q3. What is the most difficult disease to cure?
Q4. Which disease is the silent killer?
FAQs on Disease and Its Causes: Complete Guide for Students
1. What is a disease, and how is it different from simply being unhealthy?
A disease is a specific condition where the normal functioning of the body or a part of it is disturbed or impaired, leading to specific signs and symptoms. It represents a pathological process. In contrast, being unhealthy is a broader state. A person might feel tired or weak without having a specific, diagnosable disease. Health, as defined by the WHO, is a state of complete physical, mental, and social well-being, not merely the absence of disease.
2. What are the main types of diseases based on their duration? Please provide examples.
Diseases can be broadly classified into two types based on their duration:
- Acute Diseases: These diseases last for a very short period and do not cause long-term effects on health. The patient usually recovers completely. Examples include the common cold, typhoid, and cholera.
- Chronic Diseases: These are long-lasting diseases that persist over a long time, sometimes for a lifetime. They progress slowly and can have major effects on general health. Examples include diabetes, tuberculosis, and arthritis.
3. What is the fundamental difference between infectious and non-infectious diseases?
The fundamental difference lies in their cause and transmission. Infectious diseases, also known as communicable diseases, are caused by external disease-causing agents called pathogens (like bacteria or viruses) and can spread from an infected person to a healthy person. In contrast, non-infectious diseases are not caused by pathogens and cannot be spread from one person to another. They are often caused by genetic factors, nutritional deficiencies, or lifestyle choices, such as heart disease or cancer.
4. What are pathogens, and can you list the major types of infectious agents with an example for each?
Pathogens are microorganisms that can cause disease upon entering the body. They are the primary cause of infectious diseases. The major types of infectious agents include:
- Viruses: These cause diseases like the common cold, influenza, COVID-19, and measles.
- Bacteria: These are responsible for diseases such as typhoid fever, cholera, and tuberculosis.
- Fungi: They cause many common skin infections like ringworm and athlete's foot.
- Protozoa: These single-celled organisms cause diseases like malaria (caused by Plasmodium) and amoebic dysentery.
5. How do communicable diseases spread? Explain the different modes of transmission.
Communicable diseases spread through various means by which pathogens travel from an infected source to a healthy individual. The main modes of transmission are:
- Air-borne Transmission: Pathogens are transmitted through small droplets expelled when an infected person coughs or sneezes (e.g., common cold, pneumonia).
- Water-borne Transmission: Occurs when one consumes water contaminated with pathogens (e.g., cholera, amoebiasis).
- Direct Contact: Some diseases spread through physical contact with an infected person or their belongings (e.g., skin infections, chickenpox).
- Vectors: These are animals or insects that carry infectious agents from a sick person to a healthy one. For example, mosquitoes act as vectors for malaria and dengue.
6. Why are some conditions referred to as 'lifestyle diseases'? What are some common examples?
Certain non-communicable diseases are called 'lifestyle diseases' because their occurrence is primarily linked to the daily habits, diet, and environment of a person rather than an infectious agent. They arise from unhealthy lifestyle choices. Common examples include Type 2 diabetes, often linked to poor diet and obesity; heart disease, associated with high-fat diets and lack of exercise; and hypertension (high blood pressure), which can be worsened by stress and high salt intake.
7. Why is it so important to identify the exact cause of a disease for its effective treatment?
Identifying the exact cause of a disease, particularly the category of pathogen, is crucial for choosing the correct treatment. Different types of pathogens have different biological characteristics and life processes. For instance, antibiotics are effective against bacteria because they block bacterial biochemical pathways. However, these drugs do not work on viruses, which use the host cell's machinery to replicate. Using the wrong medication is not only ineffective but can also lead to drug resistance and unnecessary side effects.
8. What are the two main principles of preventing infectious diseases?
The prevention of infectious diseases is based on two main principles:
- General Principles: These involve preventing exposure to infectious agents. This includes maintaining personal and community hygiene, drinking clean water, consuming properly cooked food, providing a clean environment to prevent vector breeding, and practicing social distancing for air-borne diseases.
- Specific Principles: This involves strengthening the body's immune system so it can fight off pathogens if exposure occurs. The most effective way to do this is through immunisation or vaccination, which introduces a weakened or inactivated pathogen to stimulate the immune system to produce antibodies.
