Human Disease

HUMAN DISEASE CONTENTS         Personal hygiene : It involves individual’s cleanliness. It can be achieved by washing of soiled hand, regular cleaning of teeth, care of eyes, taking bath, wearing clean clothes, timely vaccination against dangered diseases etc. Source of Diseases Types of Diseases Means of spreading Principal of treatment Principal of Prevention  Personal & Community issue both matter for health Our social environment is an important factor in our individual health. Human begins live in societies in villages, towns or cities. In such places, even our physical environment is decided by our social environment.  Social equality and harmony : Similarly, social equality and harmony are necessary for individual helath. It involves participation in one another’s joys and sorrow, helping others and receiving help at the time of need etc. Health In is a state of being well enough to function well physically mentally & socially.   Public health services : These services ensure (i) proper removal and disposal of garbage, (ii) proper drainage of sewage, (iii) clean drinking water and unadulterated food items, (iv) vector and pest control, (v) proper vaccination and other health care services etc. If public health services are inadequate, the helath of individual citizens is bound to be affected despite taking best personal hygiene and consuming the balanced diet. Economic conditions: Food is earned by doing job. Proper earning is necessary to provide adequate and nutritious food to everyone in the family.  Differences between ‘healthy’ and ‘disease free’ Healthy 1. It is a state of physical, mental and social well being. Disease-free 1. It is a state of absence of any discomfort or derangement of the functioning of the body. 2. It refers to the individual. 2. It refers not only to the individual but also its social and community environment. 3. A ‘healthy’ individual is one 3. A ‘disease-free’ who is able to perform individual may have normal under given situation. good health or poor health Symptoms : These are the manifestations or evidences of the presence of disease(s). Symptoms indicate that there is some abnormality in the body. For instance, we have headache or cough or loose motions or wound with pus, all these are symptoms of some disease(s). On the basis of the symptoms, the physicians do the following :   They look for the signs of a particular disease. They get laboratory tests done on the patients to further confirm the disease. Signs: These provide information about the presence of particular disease. These are distinct for different diseases. Differences between symptoms and signs of diseases Symptoms The important extrinsic factors which upset human health are the following  Unbalanced diet  Diseases causing micro-organism such as viruses, bacteria, fungi etc.  Environmental pollutants. Tobacco, alcohol and narcotic drugs.  Extrinsic factors affect the health of our body by interfering with normal fuctioning of the body system. Signs 1. Symptoms indicate the presence of disease 1. Signs provide information about the presence of particular disease. 2. These are the manifestations or evidences of the presence of disease(s) of various body parts 2. These are distinct for different diseases.  Some of diseases caused by extrinsic factors are–  Kwashiorkor Marasmus  Night blindness Beri Beri etc.  Types of Diseases : Sources (causes) of Disease :   Generally, factors affecting health may be divided into following groups (a) Intrinsic factors and (b) Extrinsic factors (A) Intrinsic or Internal Factors :  The disease causing factors which exist with in the human body are called intrinsic factors.  The important intrinsic factors which affect human health are the following  Malfunctioning or improper functioning of various body parts.   Human diseases are broadly grouped into two categories Congenital Diseases :  These diseases are those which are present since birth. Acquired Diseases :  Genetic disorders  Hormonal imbalances Malfunctioning of immune system  The diseases caused by intrinsic sources or factors are called organic or metabolic diseases.  Some of the diseases caused by intrinsic sources are  Cardiac failure  Kidney failure  Osteoporosis (Pore in bones)  Myopia or short sightedness  Sickle cell anaemia etc. (B) Extrinsic or External Factor :  The factors causing diseases and existing outside the human body are called extrinsic or external factors.  These diseases are those which develop after birth. Acquired Diseases : Acquired diseases can be broadly classified into two types Communicable Non-communicable Infectious (communicable) Diseases : These diseases are spread from infected person to other in various ways, i.e., through air, water, food, physical contact, sexual act and insects. The causative agents of these diseases are called pathogens or infectious agents. These may be viruses, bacteria, fungi, protozoans (single-called animals) and different kinds of worms (multicellular organisms). Common diseases caused by these infectious agents are mentioned in Table. Infectious Agents I. Viruses II. Bacteria Diseases 1. Common cold 2. Influenza 3. Dengue fever 4. Poliomyelitis 5. Hepatitis-B 6. AIDS (Acquired Immuno Deficiency Syndrom 7. Chicken pox 8. Measles 9. Mumps 10. SARS 11. Swine Flu (H1N1) 1. Typhoid fever 2. Cholera 3. Tuberculosis  Inadequate diet or deficiency of nutrients, minerals and vitamins (e.g., Kwashiorkor, marasmus, beriberi, scurvy, night blindness etc.  Hypo or hyper secretion of hormones (e.g. diabetes, iodine-deficiency goiter, critinism, myxodema, exopthalmic goitre etc.   Malfunctioning of immune system (e.g., allergy) Cancer. Infectious diseases are also called communicable diseases because they can spread from infected person to healthy person(s). The means of spread of these diseases are different for different pathogens.  Direct Transmission : The disease causing microorganisms (pathogens) are transmitted from infected person to healthy person (s) directly in the following ways : 4. Anthrax 5. Tetanus 6. Food poisoning III. Fungi IV. Protozoans 1. Many common skin infectious (e.g., ring worm, athlete’s foot) 1. Malaria Spray of mucus-droplets that fills the air on sneezing  Physical contact with infected person : The pathogens of diseases like chicken pox, small pox, ring worm etc. are spread through physical contact with infected person or through articles of use.  Sexual Contact : Few infectious diseases such as syphilis, gonorrhoea (both caused by bacteria) and AIDS (caused by virus) are transmitted by sexual contact from one partner to the other. 2. Kala-azar 3. Amoebic dysentry 4. Sleeping sickness V. Worms 1. Intestinal worm infections (taeniasis by tape worm and ascariasis by round worm). 2. Elephantiasis Non-Infectious (non-communicable) Diseases : These diseases remain confined to the person who develops them and do not spread to other. Noninfectious diseases may occur due to :  Malfunctioning of some important body organs (e.g., heart diseases, epilepsy etc.);  Contact with soil : Many pathogens can enter the human body from soil through injuries (e.g., tetanus)  they are likely to stay in the lining of the gut (e.g., thyphoid-cuasing bacteria) or these pathogens can also go to the liver, e.g., the viruses that cuase jaundice.  Animal bites : Communicable diseases can also spread through the animal bites. For example, rabies virus enters the human body by the bite of rabid dog or monkey to cause rabies.  Indirect Transmission : It involves spread of pathogens of some diseases through some intermediate agents. Indirect transmission occurs in the following ways :  If the pathogenic microorganisms enter via mouth, Through air : Infectious microbes that cause common cold, tuberculosis, pneumonia etc. can spread through air from infected person.  Through contaminated food/water : Many infectious diseases can also spread through intake of contaminated food/water. For instance, choleracausing microbes enter new host through the water they drink and cause disease in them.  Through vectors : Many animals living with us carry the infecting agents from an infected person to other potential host. These animals act as intermediate and are termed vectors. The vectors are, therefore the carriers of the disease-causing pathogens. The most common vectors are the insects.   Houseflies carry the causative organisms of cholera, typhoid, dysentry and tuberculosis on the legs and mouth parts from faeces and sputum to the food and drinks. The latter, if taken, cause infection in others.:  Orgns-specific and tissue-specific manifestations : Compared to any type of pathogenic microbe, our body is quite large. Thus, there are many possible regions, tissues or organs, where a pathogenic microbe can go and stay. Different species of disease-causing microbes have evolved to move and reach to various parts of the body. In parts, this selection is connected to their point of entry into the body. Few cases are cited below :  If disease-cuasing microbes enter with air via the nose, they are likely to go to the lungs, e.g., bacteria which cause tuberculosis of lungs.  Virus that causes HIV infection, enters the body through sexual organs during sexual contact and then tends to spread to lymph nodes throughout the body.  Malaria-causing microbes are transmitted through mosquito bite, and move to the liver and then to the red blood cells (R.B.Cs).  Similarly, virus that causes, Japanese encephalitis (brain fever) enters the body through mosquito bite, However, it will go to reside and infect the brain.  Eradication of vectors : Vector-borne infections can be prevented by providing clean environments. The breeding places of vectors should be destroyed and adult vectors killed by suitable methods. There are to ways to treat an infectious (communicable) disease. These are -  To reduce the effects of the disease : It can be done by providing symptomatic treatment. We can  Sterilization : Patients’s surroundings and articles of use should be sterilized. Soap, phenyl, dettol, and antiseptic lotion may be used wherever necessary. provide treatment that will reduce the symptoms which are usually because of inflammation.  To kill the cause of the disease, i.e., pathogens. The most common method to kill disease-causing  Isolation : A person suffering from an infectious disease shoule be kept in isolation so that others do not catch infection from him. microbes is to use medicines that kill microbes. We have to choose a specific drug that is effective against a particular group of microbes. This is what  Education : People should be educated about the infectious disease so that they may protect themselves against such infections. is achieved by antibiotics.  Proper and sufficient food : Availability of proper (nutritious) and sufficient food to everyone will make people healthy to resist infections.  Ways of Prevention of Infectious Diseases : There are two ways of prevention of infectious diseases :   General ways  Specific ways General ways of prevention of infectious diseases : These include  Sanitation : Public hygiene is one basic key to the prevention of infectious (communicable) diseases.  Proper immunization against diseases.  Specific ways of prevention of infectious diseases : Specific ways of prevention of infectious diseases relate to a peculiar property of the immune system that usually fights off microbial infections. This is the basis of the principle of immunisation.