Notes-Class 8-General Science-Chapter-2-Health and Diseases-Maharashtra Board

Health : The state of holistic physical, mental and social well-being is called health.

• When we become sick, there is disturbance in the normal health. There is some pain in the body. One may get fever, there is headache or cough and cold. Sometimes the digestion is improper resulting into loose motions. In this way we may get uncomfortable feelings.
• Some illnesses can be treated at home with household remedies. Even if there is infection, it can be for a short period and gets cured by itself. But some of the illnesses are severe and cannot be cured in such a way. Thus a doctor’s advice and treatment is required. With doctor’s consultation and regular medicines then there is a relief.

Disease : When physical, physiological and psychological processes in the body are disturbed, then it is said to be the condition of disease. As per the disease, symptoms are varied.

Types of diseases : There are different types of diseases. They can be classified generally as follows :

According to duration :

(A) Chronic E.g. Cancer, Arthritis

(B) Acute E.g. Fever that comes up suddenly, cold.

According to causes :

(A) Hereditary diseases (Down’s syndrome, Haemophilia, etc.)

(B) Acquired diseases :

• Communicable or Infectious diseases : E.g. Cold, dengue.
• Non-communicable or Non-infectious diseases :
• g. Diabetes, Heart disorders.

Pathogen :The microbe that causes infection of some particular diseases are called pathogen.

Infectious diseases : By being in the contact of a patient, the pathogens from his or her body enter another normal person through air, water, food or other means. These pathogens create illness in a normal person, causing infectious diseases.

Some important infectious diseases : Hepatitis, Dysentery, Tuberculosis, Cholera, Typhoid

(i) Hepatitis : Viral Disease

Pathogens: Virus of hepatitis A, B, C, D, E

Mode of infection : Contaminated water, sharing of needles, transfusion of infection carrying blood.

Symptoms : Anorexia (no appetite for food). Urine dark coloured, general weakness, nausea, vomiting, grey coloured stool.

Prevention and treatment : Drinking boiled water, proper cleaning of hands

(ii) Diarrhoea and Dysentery : Viral and bacterial

Pathogens: Bacteria, virus, Shigella, bacilli, Entamoeba histolytica

Mode of infection : Contaminated water & food.

Symptoms : Watery stool, abdominal pain

Prevention and treatment : Consumption of boiled water, Keeping the food covered by proper storage of food, ORS consumption

(iii) Tuberculosis : Bacterial

Pathogens: Mycrobacterium tuberculae

Mode of infection : Patient’s spittle through air, continuous contact with patient, using things of patient.

Symptoms : Chronic cough, Bloody spittle, emaciation, difficult breathing

Prevention and treatment : BCG vaccine for protection and prevention of TB.

Isolation of patient, DOT (Daily Observed Treatment) on regular basis.

(iv) Cholera : Bacterial

Pathogens: Vibrio cholerae

Mode of infection : Contaminated water & food.

Symptoms : Vomiting, severe diarrhoea, cramps in legs

Prevention and treatment : Following hygienic practices, roadside food should not be consumed, drinking boiled water, preventive vaccination against cholera

 (v) Typhoid : Bacterial

Pathogens: Salmonelia typhi

Mode of infection : Contaminated water & food.

Symptoms : Anorexla, headache, rash seen on abdomen, loose motions, high fever reaching to 104°F

Prevention and treatment : Drinking clean water, vaccination, proper sewage disposal.

(vi) Enteritis : Viral and bacterial

Pathogens: Infectious bacteria, virus, worms or ingestion of harmful chemical substances.

Mode of infection : Contaminated water & food.

Symptoms : Stomach-ache, fever, vomiting, Anorexia, loss of body weight, loose motions and constipation alternating with each other.

Prevention and treatment : Proper medicines, ORS, Light diet, Safe food and water. Personal hygiene, covering the food.

 (vii) Leprosy : Viral and bacterial

Pathogens: Mycobacterium leprae (Bacteria)

Mode of infection : By physical contact with the patient or by using clothes, utensils and other things of the patients.

Symptoms : Effect on peripheral nervous system. Loss of sensation, losing the fingers and toes.

Prevention and treatment : Treatment with appropriate antibiotic.

 (viii) Plague : Bacterial, Spread through insects

Pathogens: Yersinia pestis (Bacteria)

Mode of infection : The bite of flea which are carriers of this bacteria.

Symptoms : Three types of plague, each with different symptoms..

Prevention and treatment : Treatment with appropriate antibiotic.

 (ix) Malaria : Spread through insects

Pathogens: Plasmodium vivax (Protozoan)

Mode of infection : Through the bite of female anopheles mosquito. Mosquito is a vector.

Symptoms : Headache and fever with chills

Prevention and treatment : Proper medicines.

 

Spread of diseases by mosquitoes :

• Malaria -> Female Anopheles mosquito
• Elephantiasis —> Female Culex mosquito
• Dengue —> Female of Aedes mosquito
• Anopheles and Aedes grow in clean water but Culex breeds in dirty, sewage water / gutters.

 

Currently important diseases : Dengue, Swine flu, AIDS

Dengue :

• Transmission : (1) Aedes aegypti. Mosquito spreads infectious disease called dengue. (2) The sickness spreads by DEN-1,2 virus belonging to the type-flavivirus.
• Symptoms : (1) Acute and severe fever. (2) Severe headache (3) Vomiting (4) Pain in the eye sockets. (5) Decrease in the count of blood platelets. (6) Internal haemorrhages in the body.
• Diagnosis : Blood test, Serological tests in the laboratories.
• Additional information : The stagnant water in Man-Made containers can cause profuse breeding ol Aedes aegypti,

 

Swine flu :

• Transmission : 1) The infection of swine flu is transmitted through pigs or infected humans.(2) The virus influenza A (H1N1) causes the infection of swine flu. (3) Spread of the disease is through sweat, secretions of nose, throat and saliva.
• Symptoms : (1) Palpitations. (2) Difficulty in breathing. (3) Sore throat. (4) Body pains.
• Diagnosis : Scrappings from patient’s throat are sent to the laboratory. The testing helps to see the occurrence of virus.
• Additional information : Diagnosis can be done at National Institute of Virology (NIV), Pune and National Institute at Communicable Diseases (NICD), Delhi.In 2009 the first case of swine flu was reported In Mexico,

 

AIDS

• Transmission : HIV (Human Immunodeficiency Virus)
• Symptoms : Symptoms are specific to every person. There is progressive weakening of natural immunity which makes a person susceptible to variety of infections. The unsafe sexual contact and the contaminated blood and blood products cause transmission of HIV.
• Diagnosis : ELISA test
• Additional information : AIDS is not transmitted through touching or sharing the food with HIV infected person. It cannot be caused by nursing the HIV patient. We can have normal behaviour with HIV infected person. For the first time HIV was reported in an African species of Monkeys. National AIDS Control Program and UNAIDS work in the research field of AIDS

 

Infections through Animals :

Rabies: This is a viral disease. It occurs due to the bite of the infected dog, rabbit, monkey, cat etc. Virus enters the brain via neurons.

Symptom : Hydrophobia is one of the important symptom of this disease. In this case, the victim shows extreme fear for water. Symptoms start to appear within 90 – 175 days of dog bite.

Treatment : Rabies is fatal disease. However, fatality can be prevented vaccination taken immediately after bite.

Non-infectious diseases : (Cancer, Diabetes, Heart Diseases)

Non-infectious or Non-communicable diseases : The diseases that are not spread through contact or through infections are called non-infectious or non-ommunicable diseases. Certain degenerative processes or some metabolic errors can cause such diseases.

(1) Cancer : Uncontrolled and abnormal cell growth is called as cancer. Group or lump of cancerous cells is called as malignant tumor. Cancer can occur in various organs like lungs, mouth, tongue, stomach, breast, uterus, skin and tissues like blood.

Reasons : Consumption of tobacco, gutkha, smoking, alcoholism, lack of fiber content (fruits and leafy vegetables) in food, excessive consumption of junk food (pizza, burger etc) are some of the many possible reasons. Heredity may also be a reason.

Symptoms :

• Chronic cough, hoarse voice, difficulty in swallowing.
• Incurable scar and inflammation.
• Lumps in breast.
• Unexplained weight-loss.

Modern diagnostics : Following techniques are used for the diagnosis of cancer

• Tissue diagnostics
• CT scan
• MRI scan
• Mammography
• Biopsy

Treatment of cancer :

• Chemotherapy
• Radiation therapy
• Surgery
• Robotic surgery
• Laparoscopic surgery

Preventive and control measures of Cancer :

• Control over diet
• Physical exercise
• Never to consume tobacco, smoking or alcoholism
• Avoiding addictions.

 

(2) Diabetes :

• In normal persons, there is secretion of insulin hormone from the pancreas. This hormone maintains the blood sugar level. In case of diabetic individuals, the secretion of insulin is either in deficiency or it is not secreted at all.
• The role of insulin is to keep control over the blood glucose level by changing the metabolism accordingly. But in case of diabetic patients, the sugar in the blood is never maintained in its normal amount.

Symptoms :

• Increased thirst
• Increased and frequent urination.
• More urge of urination at night.
• Uncontrolled weight gain or weight loss.
• Feeling of fatigue.

Causes :

• Heredity
• Obesity
• Lack of physical work or exercise
• Mental stress, anxiety

Preventive measures/Control :

• Proper diet
• Control over consumption of carbohydrates and fats.
• Taking proper medicines and treatment as per doctor’s advice.
• Physical exercise and regular walking.

Diagnosis :

• To test the blood sugar level.
• HbA1C tests.

Treatment:

• Injections of insulin or tablets that will stimulate the secretion of insulin.
• Complete control over diet.

On the international level, India has largest number of diabetic patients of about 7 crores.

(3) Heart Diseases : When the efficiency of the heart is reduced due to some causes, the heart does not perform its regular work. This causes heart disease.

• Continuous supply of blood is needed for the heart muscles.
• This blood provides oxygen and nutrients to the heart.
• When this supply is hindered the heart gets stressed. This can cause heart attack.
• In such condition, immediate treatment and doctor’s advice is a must. This can save the life of a patient.

Symptoms

• Severe chest pains,
• pains in shoulder, neck and arms,
• cramps in hand,
• uneasiness,

Reasons :

• Smoking,
• alcoholism,
• diabetes,
• hypertension,
• obesity,
• lack of physical exercise,
• heredity,
• mental stress,
• anger,

First Aid for Heart Disease :

• Immediately seeking help from 108 for calling ambulance.
• Checking whether the patient is conscious.
• Giving first aid of C.O.L.S. type i.e. Compression Only Life Support.
• In this the patient is made to lie on a hard surface in horizontal position and the pressure is given on his or her thorax to keep the heart working. The pressure and stroking is continued till the doctor arrives.

Diagnosis :

• ECG is taken to check the activity of the heart.
• Complete check-up by the cardiologist.
• Few specific blood tests.

Treatment :

• Angioplasty
• By-Pass surgery
• Open heart surgery
• Heart transplant
• Installation of stents
• Installation of pacemaker

Every disease is caused by a specific reason. They are not caused due to divine curse or hatred. People who are unaware about the scientific and medical knowledge resort to blind faith. Disease can be cured only through the proper medical treatment and care.

Viral diseases.	Bacterial diseases	Diseases spread through insects	Hereditary diseases.
AIDS, Hepatitis, Influenza, Rabies, Polio.	Typhoid, Tuberculosis, Cholera, Leprosy.	Malaria, Dengue, Elephantiasis.	Diabetes, Haemophilia, Muscular dystrophy, Colour blindness.

 

Misuse of Medicines :

• Pain killers when taken in overdose cause damage to nervous system, excretory system, liver, etc.
• Over use and unnecessary use of antibiotics can cause nausea, abdominal pain, loose motion, rashes on the body and white patches on tongue.
• Taking medicines without doctors prescription and overuse of medicines will certainly cause harmful side effects on the body.

Generic medicines :

Generic medicines or general medicines are manufactured and distributed without any patent. These medicines are comparatively much cheaper than the branded medicines. However they are equal in their quality with branded medicines.

Generic medicines are exported on a large scale by Indian companies. But in India, the same medicines are sold as branded medicines by increasing their price. In America 80% medicines used are generic and hence they save billion of dollars.

Under Pradhan Mantri Jan Aushadhi Yojana best quality medicines are made available at affordable prices to the common people. These medicines are available in ‘Jan Aushadhi Stores’. This scheme was started by the Government of India on 1st July 2015.

Lifestyle and diseases :

• Lifestyle is type of diet the routine and the pattern of thinking too.
• Right kind of lifestyle includes sufficient sleep, right food, yoga, pranayama and sufficient physical exercise.
• By wrong kind of lifestyle. there is increased frequency of ill health and episodes of diseases.

Vaccination : For prevention of the infectious diseases, preventive vaccination can be given. This saves the health of a person. By vaccinations, babies can be protected against many diseases.

Blood donation and eye donation are said to be supreme gifts any one can give. If blood donation is done 4 times in one year, 12 patients can be saved. By eye donation, some blind person may regain the sight.

Drinking boiled and filtered water :

• When water is boiled, all the disease causing pathogens present in it are killed.
• Different diseases like cholera, enteritis, diarrhoea, dysentery, hepatitis, typhoid are caused by such water-borne pathogens.
• If we boil the water we are protected against all such diseases.
• If the water is filtered we can avoid infections from nematode Dracunculus which causes Naru.
• By boiling and filtering water, even the epidemics by such infectious diseases can be controlled.

Balanced diet: The diet that contains all the nutrients in the balanced proportion is called balanced diet.

• Malnutrition can avoided by taking balanced diet.
• The immunity increases due to good proportion of vitamins and minerals present in balanced diet.
• Some diseases can be avoided due to raised immunity.
• Wrong lifestyle and wrong diet can cause hypertension, diabetes or heart disease.
• To maintain our health and keep the body in equilibrium, we have to take balanced diet.

Physical exercise/Yogasanas.  

• By exercise and yoga, the blood circulation of body is improved.
• Body and joints remain flexible. Mental strain and stress is reduced.
• Insomnia (inability to fall asleep), arthritis, indigestion, and some other disorders can be avoided.
• The person who performs exercise, always remains away from the addictions.
• Yoga makes levels of hormones, enzymes, etc. in equilibrium.
• By keeping control over breathing through pranayama many respiratory and circulatory disorders can be prevented.

Important days :

• 7th April - World Health Day
• 14th June - World Blood Donation Day
• 29th September - World Heart day
• 14th November ~ World Diabetes Day