Comprehensive General Knowledge on Diseases

The article below is a summation of general knowledge on diseases, its types, causes, names of pathogens causing diseases, common and medical names of diseases, rare diseases, syndromes, hormonal disorders and also a quiz to test yourself.

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The study of diseases is called Pathology.
What is a disease?: A disease is a medical condition or disorder that negatively affects the structure or function of an organism. It leads to impaired physiological processes and often has characteristic symptoms.

Causes of Diseases: Diseases can arise due to various factors, including pathogens (e.g., viruses, bacteria, fungi, parasites), genetic mutations, environmental factors, lifestyle choices, or a combination of these factors.

Types of Diseases and Examples

Type of DiseaseExamples
Congenital diseasesHare lip, club foot, mongolism, spastic paraplegia
Hereditary diseasesHaemophilia, albinism
Dietary deficiency diseasesScurvy, rickets, beri-beri, anaemia
Hormonal diseasesGoitre, diabetes mellitus, acromegaly, dwarfism
Infectious diseases (VIRAL)AIDS, chicken pox, common cold, german measles, influenza, jaundice, measles, mumps, poliomyelitis, rabies, dengue fever, lassa fever
Infectious diseases (BACTERIAL)cholera, whooping cough, diptheria, gonorrhoea, leprosy, pneumonia, syphilis, tetanus, typhoid, tuberculosis, plague
Infectious diseases (FUNGAL)ringworm, atheletes’ foot, thrush
Infectious diseases (PROTOZOAN)malaria, amoebic dysentery, sleeping sickness, kala-azar
Infectious diseases (WORMS)filaria, tapeworm, pinworm
Degenerative diseasesgraying of hair, baldness, presbyopia, cataract, osteoarthritis, Parkinson’s disease, arteriosclerosis
Immunological diseaseshay fever, asthma, rheumatoid, arthritis, nettle rash
Neoplastic diseaseswarts, moles, cancer

Infectious Diseases

What are Pathogens?

Pathogens are microorganisms or agents that cause disease in their host organisms. They can be biological entities such as bacteria, viruses, fungi, protozoa, and parasites. These microorganisms have the ability to invade the host's tissues, multiply, and disrupt normal physiological processes, leading to the development of a disease.
Different pathogens have different mechanisms of infection and modes of transmission. For example, bacteria like Escherichia coli can cause infections when ingested through contaminated food or water, viruses like Influenza can be transmitted through respiratory droplets, and parasites like Plasmodium species which are the causative agents of malaria can be transmitted through the bites of infected mosquitoes.

Names of Viruses and Diseases

# Virus Disease caused
1.Human immunodeficiency virusAIDS
2.Varicella zosterChicken Pox
3.Rubella (virus)German Measles
4.Rubeola (virus)Measles
5.Influenza type H1N1Swine Flu
6.Influenza type H5N1Avian Influenza (Bird flu)
7.Hepatitis virus type A, B, C, D or EViral Hepatitis
8.Polio virusPoliomyelitis
9.Dengue virus (DENV)Dengue
10.Rabies lyssavirusRabies

Names of Bacteria and Diseases

# Bacteria Disease caused
1.Vibrio choleraeCholera
2.Bordetella pertussisWhooping Cough
3.Cornebacterium diphtheriaeDiphtheria
4.Neisseria gonorrhoeaeGonorrhea
5.Mycobacterium lepraeLeprosy
6.Treponema pallidumSyphillis
7.Clostridium tetaniTetanus
8.Mycoplasma pneumoniaePneumonia
9.Salmonella typhiTyphoid
10.Salmonella paratyphiParatyphoid
11.Mycobacterium tuberculosisTuberculosis
12.Yersinia PestisPlague

Names of Other Organisms and Diseases

# Organism Disease caused
1.Plasmodium vivax, Plasmodium malariae, Plasmodium falciparumMalaria
2.Trypanosoma bruceiSleeping sickness
3.Trychophyton rubrumRingworm, Athlete's foot
4.LeishmaniaKala Azar

Deficiency Diseases and Conditions

What are Deficiency Diseases?

Deficiency diseases are health conditions that arise due to a lack of essential nutrients in the diet. These nutrients include vitamins, minerals, proteins, and other essential compounds required for proper bodily functions. Deficiency diseases can result in a range of symptoms, such as weakness, fatigue, impaired growth, and compromised immune function. Proper nutrition and a balanced diet are crucial in preventing these diseases, ensuring optimal health and well-being for individuals of all ages.
Given below are the names of certain diseases and disorders resulting from deficiency of essential nutrients.


# Name of the disease Linked with the deficiency of
1.Night BlindnessVitamin A
2.Beri BeriVitamin B
3.ScurvyVitamin C
4.RicketsVitamin D
5.SterilityVitamin E
6.Impaired blood clottingVitamin K
11.XeropthalmiaVitamin A

Common and Alternative Names of Diseases

Common NameAlternative Name
LeprosyHansen's disease
Heart AttackMyocardial infarction
Blood CancerLeukemia
Whooping CoughPertussis
Night blindnessNyctalopia
Rabbit feverTularemia
Lazy eyeAmblyopia
Chicken poxVaricella
PlagueBlack death
German measlesRubella
Athlete's FootTinea Pedis
Kala Azar, Black Fever, Dumdum FeverVisceral leishmaniasis
Sleeping SicknessHuman African trypanosomiasis

Why is Leprosy also known as Hansen's Disease?

Leprosy is also known as Hansen's disease to honor the Norwegian physician Gerhard Armauer Hansen, who discovered that a bacterium was responsible for causing the disease. In 1873, Hansen, while working as a young physician at the St. George's Hospital in Bergen, Norway, observed rod-shaped bacteria under a microscope in skin tissue samples taken from leprosy patients. He named the bacterium "Mycobacterium leprae" in honor of its association with the condition.

Why is Rabies also known as Hydrophobia?

Rabies is also known as hydrophobia due to one of its characteristic symptoms. Hydrophobia refers to an intense fear of water or the inability to drink water, and it is a prominent feature of the disease in its later stages.

Why is Tetanus also known as Lockjaw?

Tetanus is known as lockjaw because one of its main symptoms is severe muscle spasms and stiffness in the jaw muscles, leading to the inability to open the mouth or swallow. This condition is called lockjaw due to the jaw muscles becoming tight and "locked" in position.

Diseases and Body Parts Affected

# Disease Body part affected
1.Alzheimer's DiseaseBrain (memory functions)
6.COVID-19Respiratory system
7.DiphtheriaRespiratory tract
12.Grave's DiseasesThyroid
14.LeprosySkin and Peripheral nerves
15.LeukemiaBone marrow (cancer)
17.MelanomaSkin (cancer)
19.Parkinson's DiseaseBrain (motor functions)
21.RabiesCentral nervous system
24.TetanusSkeletal Muscles

Metal & Mineral Poisoning Diseases

Name of the disease Poisoning effect of
Itai ItaiCadmium
Mad Hatter's Disease (Erethism)Mercury
Minamata DiseaseMercury
Byssinosis (Brown Lung disease)Cotton Dust
White Lung diseaseAsbestos
Black Lung diseaseCoal dust
SilicosisSilica Dust
SiderosisIron Dust

Interesting Facts

Minamata Disease is so named because it was first discovered in Minamata city of Japan in 1956. It is a neurological condition caused due to the effects of methylmercury which was released in the industrial wastewater from a chemical factory. This highly toxic chemical bioaccumulated and biomagnified in shellfish and fish in Minamata Bay and the Shiranui Sea. The local population consumed the fish and were severely affected by the disease.

Itai Itai meaning "It hurts, It hurts" in Japanese was the name coined by locals in Toyoma in Japan where it first occurred in 1912. Itai-itai disease mainly affects women residing in rice farming areas irrigated by the contaminated Jinzu River in Toyama. The disease is characterised by osteomalaecia with severe bone pain and is associated with renal tubular dysfunction.

Mad Hatter's disease Mercury was used in hat making in the 19th century and hat makers who inhaled mercury vapours exhibited symptoms of the disease and hence the name. Affected persons exhibit symptoms like vomiting, skin rashes, tremors, twitching, and excitability.

zoonotic diseases

What are Vectors?

Vectors are living organisms that can transmit pathogens from one host to another. They act as intermediaries in the transmission of infectious diseases, transporting the pathogen from an infected individual (the reservoir) to a susceptible individual (the new host). Vectors can be arthropods, such as mosquitoes, ticks, and fleas, or other animals, such as rodents.
Vector-borne diseases are commonly associated with insect or arthropod vectors that act as carriers for pathogens. For example, mosquitoes can transmit diseases like malaria, dengue fever, Zika virus, and West Nile virus, while ticks are responsible for spreading Lyme disease.

Zoonotic Diseases and Reservoirs and Carriers

Diseases which can be transmitted from animals to humans and vice-versa are called zoonotic diseases.
Reservoirs and Carriers: Animals that carry zoonotic diseases without necessarily transmitting them to other hosts are considered reservoirs or carriers. These animals may host the infectious agents in their bodies and can serve as a source of infection for humans and other animals. However, they do not play an active role in transmitting the disease from one individual to another. For example, rodents can be reservoirs for hantaviruses, and birds can be reservoirs for avian influenza.

The table below gives the names of vectors/reservoirs and associated diseases

Diseases transmitted by Animals

Animal/Bird/Insect Disease
Tsetse flySleeping Sickness
Sand flyKala Azar
Anopheles mosquitoMalaria
Aedes MosquitoDengue, Yellow Fever, Chikungunya
Culex MosquitoWest Nile Fever
RodentsBubonic Plague
RodentsHantavirus Syndromes
Dogs, Bats, RaccoonsRabies
Animals in generalAnthrax
Rabbits, Hares & RodentsTularemia
PoultryAvian Influenza or Bird Flu
Pigs (through Culex mosquitoes)Japanese Encephalitis
TicksCrimean-Congo Haemorrhagic Fever, Lyme
Fruit batsNipah virus infection

Rare Disorders and Conditions

Parkinson's DiseaseIt is a degenerative disorder of the central nervous system that impairs motor skills, cognitive processes, and other functions.
Alzheimer's DiseaseIt is form of dementia characterised by loss of memory, thinking, and changes in behavior.
Down's SyndromeAlso called Trisomy 21, it is a condition in which extra genetic material causes delays in the way a child develops, both mentally and physically.
Korsakoff's SyndromeIt is a neurological disorder caused by the lack of thiamine (vitamin B1) in the brain.
BulimiaIt is an eating disorder characterized by restraining of food intake for a period of time followed by an over intake or binging period that results in feelings of guilt and low self-esteem.
AnorexiaIt is an eating disorder characterized by refusal to maintain a healthy body weight and an obsessive fear of gaining weight, often coupled with a distorted self image
ProgeriaIt is an extremely rare genetic condition wherein symptoms resembling aspects of aging are manifested at an early age.
DyslexiaIt is a developmental reading disorder resulting from the inability to process graphic symbols.

Hormone related Diseases

Diseases Brief details
Graves DiseaseNamed after Robert Graves, the doctor who first described it, is an autoimmune thyroid disease where the thyroid gland is stimulated by autoantibodies which make it overactive, resulting in increased thyroid hormone production.
Addison's DiseaseAddison's disease is caused by damage to the adrenal glands which make hormones to control the body’s response to stress and balance body salt and water.
Diabetes MellitusIt is common condition in which the body is unable to produce enough of hormone insulin resulting in high levels of sugar in bloodstream.
AcromegalyIt is a condition caused by the overproduction of growth hormone. It leads to an increase in size of the hands and feet, thickening of the skin and a change in the appearance of the face.
Cushing's SyndromeCaused due to excess production of hormone Cortisol or by taking excess steroid medication to treat conditions like asthma, eczema etc.

Endemic, Epidemic & Pandemic

An endemic disease is the one that is consistently present but limited to a particular region or area. Like malaria which is consistently present in Africa and Asia or Chagas diseses which is endemic to Latin America.

An epidemic is said to occur when there is an increase, often sudden, in the number of cases of a disease above what is normally expected in that population in that area.

A pandemic is the worldwide spread of a new disease. This may happen due to a new type or new strain of a virus, bacteria etc.

Quiz on Diseases

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1. Which of the following is a bacterial disease?

2. What kind of disease is osteoarthritis?

3. Which of the following is a hereditary disease?

4. Which of the following is a viral disease?

5. What is the causative agent of malaria?

6. Which of the following is NOT an infectious disease?

7. Which of the following is a fungal disease?

8. What kind of disease is arthritis?

9. Which disease is caused by Bordetella pertussis?

10. Which of these causes Chicken Pox?

11. Trypanozoma brucei is responsible for causing which disease?

12. Trychophyton rubrum causes which of the following diseases?

13. The virus named DENV is responsible for which disease?

14. Which of the following is the causative agent of Syphillis?

15. Which of the following is the causative agent of Plague?

16. Which of the following is the causative agent of Malaria?

17. Deficiency of which mineral causes goitre?

18. Deficiency of niacin causes which of the following conditions?

19. Rickets is a disease caused by the deficiency of which vitamin?

20. A diet deficient in vitamin A is likely to cause which of the following diseases?

21. Deficiency of which mineral causes anaemia?

22. Kwashiorkar is a condition caused by the deficiency of which of the following nutrients?

23. By which name is Pertusis commonly known?

24. Amblyopia is the other name for which condition?

25. If a man has myocardial infarction, he has?

26. Which disease was commonly known as Black Death?

27. Alopecia is more commonly known as -

28. A man suffering from Lockjaw is to be treated for which disease?

29. Which of the following is the common name for Myopia?

30. Which disease is also known as Hansen's disease?

31. Which of the following glands is related to Grave's disease?

32. The disorder which affects the motor functions of the brain is -

33. Which organ is chiefly affected by typhoid?

34. Which of the following is a disease of the gums?

35. Which of the following is affected by Psoriasis?

36. Which of the following chiefly affects the central nervous system?

37. Melanoma is a type of cancer affecting which part of the body?

38. Which of the following is caused due to contamination by Mercury?

39. Black Lung disease is caused by the poisoning effect of -

40. Which disease is caused by the poisoning effect of Cadmium?

41. Byssinosis is caused due to which of the following?

42. Mesothelioma is a disease caused by the poisoning effect of -

43. White lung disease is caused due to the poisoning effect of -

44. Which of the following diseases is transmitted through rodents?

45. Which of the following causes sleeping sickness?

46. Dengue and chikungunya are mainly transmitted through the bites of which mosquitoes?

47. Which animals are associated with the transmission of Japanese Encephalitis?

48. Which of the following animals is associated with the spread of tularemia?

49. Which of the following is the cause of the disease kala azar?

50. Which of the following is also known as Trisomy 21?

51. Which of the following is an eating disorder?

52. Which of the following is caused due to excess production of hormone cortisol?

53. Which of the following is a reading disorder?

54. Grave's disease is associated with the overactivity of which gland?

55. In which disorder, symptoms of ageing appear at an early age?

56. Which of the following is caused by the deficiency of Vitamin B1?

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Quiz on Diseases