Diseases and their Causes

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Definition
It is an impairment of the normal state of a human being that interrupts or modifies its vital functions.
The study of disease is called pathology, which includes the study of cause.
There are four main types of disease:
1.      Infectious diseases
2.      Deficiency diseases
3.      Genetic diseases (both hereditary and non-hereditary)
4.      Physiological diseases.
Infectious Diseases
Infectious disease is a process caused by a microorganism that impairs a person’s health.
The agents of infection can be divided into different groups on the basis of their size, biochemical characteristics, or manner in which they interact with the human host. The groups of organisms that cause infectious diseases are categorized as bacteria, viruses, fungi, and parasites.
Bacteria
Bacteria can survive within the body but outside individual cells. Some bacteria, classified as aerobes, require oxygen for growth, while others, such as those normally found in the small intestine of healthy persons, grow only in the absence of oxygen and, therefore, are called anaerobes. Most bacteria are surrounded by a capsule that appears to play an important role in their ability to produce disease.
Bacterial infections can be treated with antibiotics.


List of Disease caused by Bacteria

Disease
Agent
Organ Infected
Anthrax
Bacillus anthracis
Skin, Lungs, Intestine
Botulism
Clostridium botulinum
Neuromuscular junction
Brucellosis
Brucellamelitensis
Spleen, Lymph glands
Bubonic plague
Yersinia pestis
Lymph node
Cholera
Vibrio cholerae
Small intestine
Conjunctivitis
Pyogenic bacteria
Eye
Diphtheria
Corynebacteriumdiphtheriae
Blood, Nerve fibres, Lymph node, Skin
Gonorrhea
Neisseria gonorrhoeae
Urethra, Cervix, Eyes, Fallopian Tubes,
Leprosy (Hansen's disease)
Mycobacterium lepromatosis
Epididymis skin, Bones, Peripheral nerves
Pertussis (Whooping cough)
Bordetella pertussis
Respiratory tract
Psittacosis (Parrot fever)
Chlamydia psittaci
Lungs
Q fever
Coxiellaburnetii
Lungs
Rickettsialpox
Rickettsia akari
Blood, Skin
Salmonellosis
Bacteria of the Salmonella type
Intestine
Shigellosis
Shigella
Intestine
Syphilis
Treponemapallidum
Skin, Cardiovascular Organs
Tetanus (Lockjaw)
Clostridium tetani
Nerves at synapse
Trachoma
Chlamydia trachomatis
Eyes
Tuberculosis
Mycobacterium tuberculosis
Lungs, heart, liver, brain, skin and bones.
Typhoid fever
Salmonella typhi
Gastrointestinal tract
Viruses
Viruses are not, strictly speaking, living organisms. Instead, they are nucleic acid fragments packaged within protein coats that require the machinery of living cells to replicate. Viruses are visible by electron microscopy. Vaccination has been the most successful weapon against viral infection.


List of Disease caused by Viruses

Disease
Virus Type
Agent
Organ Infected
Adenovirus Infections
DNA
Adenovirus
Lungs, Eyes
AIDS
RNA
Human Immunodeficiency Virus
T-lymphocytes
Arbovirus Encephalitis
Many RNA viruses
Arbovirus
Brain
Chicken pox ( Varicella)
DNA
Varicella-zoster virus
Skin, Nervous System
Common Cold
RNA
Rhinovirus
Upper Respiratory Tract
Cytomegalovirus Disease
DNA
Cytomegalovirus
Blood, Lungs
Dengue Fever
RNA
Dengue virus
Blood, Muscles
Ebola
RNA
Ebola
whole body
German Measles ( Rubella)
RNA
Rubella virus
Skin
Hepatitis A
RNA
Hepatitis A       virus
Liver
Hepatitis B
DNA
Hepatitis B       virus
Liver
Herpes Simplex
DNA
Herpes simplex virus
Skin, Pharynx, Genital organs
Influenza
RNA
influenza virus
Respiratory Tract
Measles ( Rubeola)
RNA
Rubeola virus
Respiratory Tract, Skin
Mumps (Epidemic Parotitis)
RNA
Paramyxoviridae
Salivary Glands, Blood
Polio
RNA
Enterovirus
Intestine, Brain, Spinal Cord
Rabies
RNA
Rabies virus
Brain, Spinal cord
Respiratory Syncytial Disease
RNA
Human respiratory syncytial virus
Respiratory Tract
Small Pox (Variola)
DNA
Variola virus
Skin, Blood
Warts
DNA
Human papilloma virus
Skin
Yellow Fever
RNA
Yellow Fever virus
Liver, Blood
Fungi
Fungi are large organisms that usually live on dead and rotting animal and plant matter. They are found mostly in soil, on objects contaminated with soil, on plants and animals, and on skin, and they may also be airborne. Specific types of antibiotics known as antifungal are effective in their treatment.


List of Disease caused by Fungi

Disease
Agent
Organ Infected
Blastomycosis
Fungus Blastomyces
Skin
Asthama
Fungus Asperigillus
Lungs
Candiasis
Yeast Candida
Skin, Mucuos Membrane
Cryptococcus Neofomans Infection
Fungus  Cryptococcus Neofomans
Brain, Lungs
Cryptococcus Gatti Infection
Fungus Cryptococcus Gatti
Sinuses, Brain, Lungs
Histoplasmosis
Fungus Histoplasma
Lungs
Mucormycosis
Mucorales
Sinuses, Brain, Lungs
Pneumocystis Pneumonia
Fungus Pneumocystis Jirovecii
Lungs
Sporotrichosis
Sporothrix
Skin , Lungs
Ringworm
Microsprum
Skin
Tineapedis (Athlete’s foot)
Tineapedis
Skin
Parasites
Among the infectious parasites are the protozoa, unicellular organisms that have no cell wall, that cause such diseases as malaria. Parasitic infections are diagnosed and treated with drugs.


List of Disease caused by Parasites

Disease
Agent
Amoebiasis
Entamoebahistolytica
Giardiasis
Giardia intestinalis
African Sleeping Sickness
Trypanosoma
Cutaneous Leishmaniasis
LeishmaniaTopica
Visceral Leishmaniasis (Kala-Azar)
LeishmaniaDonovani
Toxoplasmosis
Toxoplasma gondii
Malaria
Plasmodium falciparum, P. ovale, P. vivax and P. malariae
Babesiosis
Babesia
Deficiency Diseases
Diseases that are caused by the lack of some particular nutrient in a person's diet are called deficiency diseases.
1. Night-blindness
A child having this disease is unable to see properly in the dark. His eyes become dull and listless and the skin becomes dry. If not treated in time, the child may become blind.
Cause: This disease is caused due to the deficiency of vitamin A in the diet.
Treatment: A child suffering from night-blindness should take a diet rich in vitamin A. Carrots, fish, fruits, milk, butter, etc., are all good sources of vitamin A.
2. Beri-beri
This is basically a disorder of the nerves. It affects the health of eyes % and skin, growth of the body, formation of muscles and blood. There may also to be stomach and intestinal disturbances.
Cause: This disease is caused due to the deficiency of vitamin-B.
Treatment: The affected child must eat the foods rich in vitamin B like milk, fish, meat, cereals, egg, etc., and also seek medical advice from a doctor.
3. Scurvy
People suffering from scurvy have swollen, bleeding gums. They lose weight and become weak. Their teeth start shaking and become loose.
Cause: This disease is caused due to the deficiency of vitamin-C.
Treatment: Oranges, citrus fruits, cabbage, amla, etc., should be included in the diet of the patient.
4. Rickets:
In this disease, the bones of the legs become thin, deformed and curved (bow-legged). The bones of the child become weak and soft.
Cause: This disease is caused due to the deficiency of vitamin D.
Treatment: The affected child must eat the foods rich in vitamin D like milk, fish, meat, butter, egg, etc.
5. Anaemia
In this disease, the level of the haemoglobin becomes low gets tired very easily and feels weak. The skin becomes pale. The lips and nails become dull and colourless.
Cause: This disease is caused due to the deficiency of iron.
Treatment: The person should have plenty of green, leafy vegetables like spinach and cabbage. Meat, apples, beans, dry fruits, etc., should be included in the diet.
6. Goitre
In this disease, there is swelling around the neck region of a person.
Cause: This disease is caused due to the deficiency of iodine.
Treatment: The affected person needs to add iodised salt to his or her food.
7. Malnutrition
A child in this condition becomes weak and thin. He shows poor growth compared to other children. He gets tired easily. There may be swelling on the feet and hands. The hair becomes very thin and skin of the child gets dark and starts peeling. Such a child is said to be suffering from malnutrition.
Cause: Deficiency of proteins and carbohydrates causes this disease.
Treatment: Patients of this deficiency should eat food rich in proteins and carbohydrates. Milk, cereals, starch and sugars, meat and eggs should be a part of their diet.
Genetic Diseases
A genetic disease is any disease that is caused by an abnormality in an individual's genome. Some genetic disorders are inherited from the parents, while other genetic diseases are caused by acquired changes or mutations in a pre-existing gene or group of genes. Mutations can occur either randomly or due to some environmental exposure. Some examples of Genetic Diseases are
1.      Sickle cell anaemia
2.      Marfan syndrome
3.      Huntington's disease
4.      High blood pressure
5.      Alzheimer's disease
6.      Arthritis
7.      Diabetes
8.      Cancer
9.      Obesity.
Physiological Diseases
A disease that is not contagious is called a non-infectious disease. These diseases are not caused by pathogens. Instead, they are likely to have causes such as lifestyle factors, environmental toxins, or gene mutations. Common types of non-infectious diseases include cancer, diabetes, and immune system diseases.
Cancer
Cancer is a disease in which cells divide out of control. Normally, the body has ways to prevent cells from dividing out of control. However, in the case of cancer, these ways fail. The rapidly dividing cells may form a mass of abnormal tissue called a tumour.
Diabetes
Diabetes is another type of non-infectious disease. Diabetes occurs when the pancreas doesn’t make enough insulin or else the body’s cells are resistant to the effects of insulin. Insulin is a hormone that helps cells to absorb glucose from the blood. It is of 2 types
·        Type 1 Diabetes
Type 1 Diabetes is caused by the immune system attacking and destroying normal cells of the pancreas. As a result, the cells can no longer produce insulin. This type of diabetes usually develops in childhood or adolescence.
·        Type 2 Diabetes
Type 2 Diabetes is much more common than type 1 diabetes. Type 2 diabetes occurs when body cells no longer respond normally to insulin. The pancreas still makes insulin, but the cells of the body can’t use it. Being overweight and having high blood pressure increase the chances of developing type 2 Diabetes. This type of diabetes usually develops in adulthood. However, it is becoming more common in teens and children because more young people are overweight now than ever before.
Parkinson's disease (PD)
Parkinson's disease (PD) is a long-term degenerative disorder of the central nervous system that mainly affects the motor system. The symptoms generally come on slowly over time. Early in the disease, the most obvious are shaking, rigidity, slowness of movement, and difficulty with walking. Thinking and behavioural problems may also occur.
Vitamins and Minerals
Vitamins
A vitamin is an organic compound and an essential nutrient that an organism requires in limited amounts. An organic chemical compound (or related set of compounds) is called a vitamin when the organism cannot synthesize the compound in sufficient quantities, and it must be obtained through the diet; thus, the term vitamin is conditional upon the circumstances and the particular organism. For example, ascorbic acid (one form of vitamin C) is a vitamin for humans, but not for most other animals. Vitamin D is essential only for people who do not have adequate skin exposure to sunlight, as ultraviolet light promotes synthesis in skin cells. Thirteen vitamins are universally recognized at present.
Vitamins have diverse biochemical functions. Some, such as vitamin D, have hormone-like functions as regulators of mineral metabolism, or regulators of cell and tissue growth and differentiation (such as some forms of vitamin A). Others function as antioxidants (e.g., vitamin E and sometimes vitamin C). The B complex vitamins function as enzyme cofactors (coenzymes) or the precursors for them; coenzymes help enzymes in their work as catalysts in metabolism.


List of Vitamins

Vitamins
Chemical Name
Solubility
Disease
Sources
A
Retinol, retinal, and four carotenoids



Fat
Night blindness, hyperkeratosis, and keratomalacia
Liver, orange, ripe yellow fruits, leafy vegetables, carrots, pumpkin, squash, spinach, fish, soy milk, milk
B1
Thiamine



Water
Beriberi, Wernicke-Korsakoff syndrome
Pork, oatmeal, brown rice, vegetables, potatoes, liver, eggs
B2
Riboflavin



Water
Ariboflavinosis, glossitis, angular stomatitis
Dairy products, bananas, popcorn, green beans, asparagus
B3
Niacin, niacinamide, Nicotinamideriboside



Water
Pellagra
Meat, fish, eggs, many vegetables, mushrooms, tree nuts
B5
Pantothenic acid



Water
Paresthesia
Meat, broccoli, avocados
B6
Pyridoxine, pyridoxamine, pyridoxal



Water
Anemia, peripheral neuropathy
Meat, vegetables, tree nuts, bananas
B7
Biotin



Water
Dermatitis, enteritis
Raw egg yolk, liver, peanuts, leafy green vegetables
B9
Folates



Water
Megaloblasticanemia and birth defects
Leafy vegetables, pasta, bread, cereal, liver
B12
Cyanocobalamin, hydroxocobalamin, methylcobalamin, adenosylcobalamin


Water
Pernicious anemia
Meat, poultry, fish, eggs, milk
C
Ascorbic Acid


Water
Scurvy
Many fruits and vegetables, liver
D
Cholecalciferol (D3), Ergocalciferol (D2)


Fat
Rickets and osteomalacia
Fish, eggs, liver, mushrooms
E
Tocopherols, tocotrienols


Fat
sterility in males and miscarriage in females
Many fruits and vegetables, nuts and seeds
K
Phylloquinone, menaquinones


Fat
Bleeding diathesis
Leafy green vegetables such as spinach, egg yolks, liver
Minerals
A mineral is a chemical element required as an essential nutrient by organisms to perform functions necessary for life. Minerals originate in the earth and cannot be made by living organisms. Most of the minerals in a human diet come from eating plants and animals or from drinking water.

The five major minerals in the human body are calcium, phosphorus, potassium, sodium, and magnesium. All of the remaining elements in a human body are called "trace elements". The trace elements that have a specific biochemical function in the human body are sulphur, iron, chlorine, cobalt, copper, zinc, manganese, molybdenum, iodine and selenium.


List of Minerals

Minerals
Amount
Category
Dietary Sources
Potassium
Major


A systemic electrolyte and is essential in coregulating ATP with sodium
Sweet potato, tomato, potato, beans, lentils, dairy products, seafood, banana, prune, carrot, orange
Chlorine
Major


Needed for production of hydrochloric acid in the stomach and in cellular pump functions
Table Salt
Sodium
Major


A systemic electrolyte and is essential in coregulating ATP with potassium
Table salt (sodium chloride, the main source), sea vegetables, milk, and spinach.
Calcium
Major


Needed for muscle, heart and digestive system health, builds bone, supports synthesis and function of blood cells
Dairy products, eggs, canned fish with bones, green leafy vegetables, nuts, seeds, thyme, oregano, dill, cinnamon
Phosphorus
Major


A component of bones (see apatite), cells, in energy processing, in DNA and ATP (as phosphate) and many other functions
Red meat, dairy foods, fish, poultry, bread, rice, oats.
Magnesium
Major


Required for processing ATP and for bones
Spinach, legumes, nuts, seeds, whole grains, peanut butter, avocado
Sulphur
Major


Human body uses sulphur for nervous system function as well as to produce healthy hair, cartilage, skin and nails.
broccoli, cauliflower, onions and Brussels sprouts
Zinc
Trace


Pervasive and required for several enzymes such as carboxypeptidase, liver alcohol dehydrogenase, and carbonic anhydrase
Oysters, red meat, poultry, nuts, whole grains, dairy products
Manganese
Trace


A cofactor in enzyme functions
Grains, legumes, seeds, nuts, leafy vegetables, tea, coffee
Copper
Trace


Required component of many redox enzymes, including cytochrome c oxidase
Liver, seafood, oysters, nuts, seeds; some: whole grains, legumes
Iodine
Trace


Required for synthesis of thyroid hormones, thyroxine and triiodothyronine and to prevent goiter:
Seaweed , grains, eggs, iodized salt
Chromium
Trace


Involved in glucose and lipid metabolism, although its mechanisms of action in the body and the amounts needed for optimal health are not well-defined
Broccoli, grape juice (especially red), meat, whole grain products
Molybdenum
Trace


The oxidases xanthine oxidase, aldehyde oxidase, and sulphite oxidase
Legumes, whole grains, nuts
Selenium
Trace


Essential to activity of antioxidant enzymes like glutathione peroxidase
Brazil nuts, seafoods, organ meats, meats, grains, dairy products, eggs
Iron
Trace


Required for many proteins and enzymes, notably hemoglobin to prevent anemia          
Meat, seafood, nuts, beans, dark chocolate





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