Human Diseases

Reviewed by:

Nafeez Khan

List of Human Diseases

The human body is just like machinery that runs smoothly until it is afflicted by diseases. Any disease can be described as the malfunctioning or improper functioning of any part of the body. These malfunctions of the body include genetic disorders, hormonal imbalances, and malfunctioning of the immune system of the body. These diseases affect human health and prevent the body as well as the mind from working normally. Scientific research has provided us with extensive information about different types of diseases and their causes and prevention.

The list of diseases in humans includes those caused by intrinsic sources and extrinsic sources. The types of human diseases caused by intrinsic sources are also called organic or metabolic diseases and include ailments like kidney failure, cardiac failure, cancer, diabetes, and allergies, etc. Diseases caused by extrinsic factors include scurvy, Kwashiorkor, night blindness, obesity, etc.

Some human diseases are caused by microorganisms such as viruses, bacteria, and fungi, protozoans, helminths, and worms that enter the body through an unbalanced diet. External or extrinsic factors like environmental pollutants, alcohol, tobacco, and narcotic drugs also disturb human health. We have here a list of diseases and their causes that affect the human body.

Other Common Diseases and their Causative Agents

Cancer: It is characterized by the uncontrolled growth and division of cells leading to the generation of a mass of cells known as neoplasm. When there is an abnormal and persistent cell division localized in a particular region the tumor is considered benign.

Gout: Gout is caused by the accumulation of uric acid crystals in the synovial joints. This disease is associated with an imbalance of uric acid metabolism that causes an increase in the production of uric acid or interferes with its excretion.

Hemophilia: This disease is also called bleeder's disease and is a sex-linked disorder. Haemophilia is a recessive condition and patients suffering from this also face a blood clotting deficiency.

Haemophilia A: This ailment is characterized by a lack of anti- hemophilia globulin factor VIII. About four-fifths of hemophilia cases fall under this category.

Haemophilia B: Also called Christmas disease, it is caused by a defect in the plasma thromboplastin component.

Hepatitis: It is a viral disease that causes hepatic anorexia and results in liver damage (liver cancer) or jaundice. This disease is transmitted through the fecal-oral route and children as well as young adults are susceptible to it. Currently, there is no acceptable vaccine available for this ailment.

Different types of diseases and their causes

Table of Viral Diseases And their Causes

Human Disease Name	Cause	Affected Body Parts	Transmission Method	Vaccination Type
Influenza	Myxovirus (RNA virus)	Respiratory passages: the epithelial lining of the trachea and bronchi.	Droplet infection	Killed virus
Smallpox	Variola virus (DNA virus)	Respiratory passages, skin	Droplet Infection (Through open wounds in the skin)	Living attenuated virus is applied by scratching the skin. Eradicated.
Common cold	Commonly rhino-virus (RNA Virus)	Respiratory passages	Droplet infection	Intramuscular injection
Mumps	Paramyxovirus (RNA virus)	Respiratory passages, infection through blood, salivary glands, and testes in adult males	Droplet infection	Living attenuated virus
Chickenpox	Varicella-zoster	Blisters, skin rash	Air-borne droplets	Living attenuated virus
German measles (Rubella)	Rubella virus	Respiratory passages, lymph nodes in neck, eyes, and skin. Causes complications in pregnancy.	Droplet infection	Living attenuated virus
Poliomyelitis (polio)	Poliovirus (RNA Virus)	Pharynx and intestines, blood; motor neurons in the spinal cord, paralysis may also occur	Droplet infection, through human feces	Living attenuated virus given orally
Measles	Paramyxovirus (RNA virus)	Respiratory passages, spreads to the skin and intestines.	Droplet infection	Living attenuated virus
AIDS	Retrovirus (RNA virus)	Skin cancer	Sexual intercourse homo and heterosexuals	No vaccine available
Ebola hemorrhagic fever	Ebola Virus Disease (EVD)	Fatal illness in humans, Fever	It is transmitted to people from wild animals. Also spreads through human-to-human transmission	No licensed vaccine available
Zika	Zika Virus (mosquito-borne disease)	Mild illnesses like dengue, yellow fever	This infection in pregnant women is linked to abnormally small heads in their babies	No vaccine available
Yellow Fever	Arbovirus i.e arthropod-borne virus (RNA Virus)	Lining of blood vessels and liver	Vector- arthropods such as ticks, mosquitoes	Living attenuated virus
Covid	Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)	Primarily lungs	Respiratory virus spread through droplet infection	Living attenuated vaccine and vector vaccine

Table of Bacterial Diseases And their Causes

Human Disease Name	Cause	Affected Body Parts	Transmission Method	Type of Vaccination or Antibodies
Tuberculosis (TB)	Mycobacterium tuberculosis	Primarily lungs	Droplet infection, Milk from infected cattle	BCG living attenuated bacteria. Antibiotics such as streptomycin
Diptheria	Corynebacterium diphtheria	Upper respiratory tract, mainly throat. Hearing may also be affected	Droplet infection	Toxoid
Gonorrhea	Neisseria gonorrhea	Reproductive organs: mucous membranes of the urinogenital tract. Infants may acquire serious eye infections if they pass through an infected birth canal	Sexual contact	Antibiotics such as penicillin, streptomycin
Whooping cough (Pertussis)	Bordetella pertussis	Upper respiratory tract, violent coughing	Droplet infection	Killed bacteria
Syphilis	Treponema pallidum	Reproductive organs, eyes, bones, joints, central nervous system, heart, and skin.	Sexual contact	Antibiotics like penicillin
Cholera	Vibrio cholera	Alimentary canal: mainly small intestine.	Fecal contamination (a) food, waterborne when water is contaminated with feces from an infected person. (b) handling of contaminated objects. (c) vectors like. flies moving from human feces to food.	Killed bacteria: short-lived protection which is not always effective. Antibiotics like tetracyclines, chloramphenicol.
Tetanus	Clostridium tetani	Blood. Toxins affect motor nerves of the spinal cord and muscles which causes lockjaw	Wound infection	Toxoid
Bacterial dysentery	Shigella dysenteriae	Alimentary canal, primarily the ileum, and colon	Same as cholera	No vaccine
Typhoid	Salmonella typhi	Alimentary canal, spreads to lymph, blood, lungs, bone marrow, spleen.	Same as cholera	Killed bacteria (TAB vaccine)
Bacterial food poisoning (gastroenteritis or salmonellosis)	Salmonella spp.	Alimentary canal	Mainly foodborne. Meat from infected animals. Also through fecal contamination	Antibiotics like. tetracyclines

Diseases Caused By Worms

Human Disease Name	Pathogen Responsible/Habitat	Mode of Transmission	Main Symptoms
Ascariasis	Ascaris Lumbricoides; small intestine (jejunum) of man	Person-to-person transmission, ripe eggs passed through feces, spreads through ripe Ascaris eggs in raw vegetables.	Larvae in lungs cause pneumonia. May cause typhoid-like fever, protein and Vitamin-A deficiencies that result in protein-calorie malnutrition and night blindness. Can also cause appendicitis, jaundice.
Ancylostomiasis or 'Hook-worm disease'	Ancylostoma duobenale, small intestine (jejunum) of man	Person-to-person transmission, filariform larvae passed through feces, walking barefoot on faecally contaminated soil.	Dermatitis; reddish, severe anemia; duodenal ulcer, constipation. Pale puffy face with swelling on lower eyelids.
Enterobiasis or 'Pinworm disease'	Enterobius vermicularis, caecum, and vermiform appendix	Ingestion of eggs through contaminated food or drink.	Eczematous condition round the anus, bedwetting at night, inflammation of the vermiform appendix.
Filariasis	Wuchereria Bancrofti, lymphatic vessels, and lymph nodes.	Mosquito bite deposits larvae on the skin which enters through puncture wound and reach lymphatic channels	Elephantiasis is the enormous enlargement of the leg, scrotum, penis, labia, breast, clitoris, forearm.

FAQs on Human Diseases

1. How are human diseases classified?

A list of diseases in humans can be classified on the basis of the character, nature, mode, and causes of their spread. There are primarily two classifications: Congenital diseases and Acquired diseases.

2. What are congenital diseases?

Congenital diseases are present in the human body since birth and are caused due to genetic abnormality, metabolic disorders, or malfunctioning of any organ in the body. These types of human diseases are generally permanent, not easily curable, and may be genetic (inherited from the parents). They include medical issues like Harelip, Cleft Palate, and Club foot, etc. Sometimes an imbalance in the chromosomes causes Mongolism or a newborn has a cardiac disorder. These are also examples of congenital diseases.

3. What are acquired diseases?

Acquired diseases are defects or disorders which are not present by birth but appear in the human body due to various factors. These may be further classified into:

(i) Communicable or Infectious Diseases: These diseases are caused by a host of pathogenic viruses, protozoa, bacteria, worms, and fungi. These pathogens are generally transmitted with the help of a vector.

(ii) Non-Communicable or Non-Infectious Diseases: These diseases are also called degenerative diseases and occur due to the malfunctioning of an organ or the organ system in the human body. Deficiency diseases are also a part of non-communicable diseases. These diseases occur due to the deficiency of some minerals, nutrients, or vitamins. Other diseases that are also a part of non-communicable diseases are allergy, cancerous diseases, and genetic diseases.

4. What is the list of human diseases that spread through blood transfusion?

A common disease that spreads through blood transfusion is AIDS (Acquired Immuno Deficiency Syndrome). This disease destroys the immune system of the body and is caused by the Human Immunodeficiency Virus (HIV). There are two types of HIV: HIV-1 and HIV-2 but the virus commonly associated with AIDS is HIV-1. A virus present in the blood of the wild African green monkey is called the Simian Immunodeficiency Virus (SIV) and it is similar to HIV-2. HIV is a retrovirus and can synthesize DNA from RNA. The major cell infected by HIV is the helper T-Lymphocyte which bears the CD-4 receptor site. HIV gradually destroys T-Lymphocytes causing the patient to occasionally suffer from swollen lymph nodes, diarrhea, mild prolonged fever, and a few other non-specific symptoms.