- Health is defined as a state of physical, mental and social
well-being and does not merely mean absence of any disease.
disease is a condition in which the normal state of mind,
body and well-being of a person is impaired.
can be broadly classified as:
- Infectious or Communicable diseases.
- Non-infectious or Non-communicable diseases.
- Genetic diseases.
that are caused by pathogens and can be transmitted from one person
to another are called Communicable diseases.
that are caused by factors other than pathogens and are not
transmitted from one person to the other are called Non-communicable
diseases. Example: Arthritis.
that are caused due to changes in the genes and are transmitted to
future generations are called Genetic diseases. Example: Colour-blindness.
means inflammatory condition of the liver.
are two main types of hepatitis:
hepatitis is caused by certain chemicals, drugs or alcohol.
most common forms of viral hepatitis are hepatitis A and hepatitis
Hepatitis A: It is a highly communicable disease, commonly
known as epidemic jaundice.
Causative Agent: HAV (Hepatitis 'A' Virus).
Mode of Spread: It mainly spreads through faeco-oral
route; for example, by consuming contaminated food and water or
through prolonged personal contact with the patient.
- Toxic hepatitis
- Viral hepatitis
- Fever, loss of appetite, nausea and vomiting.
- Yellowness of skin, eyes, nails and urine.
- Maintenance of personal and domestic hygiene.
- Use of boiled water for drinking.
- Hepatitis B: It is also known as serum hepatitis.
- Causative Agent: HBV(Hepatitis 'B'
- Mode of Spread:
- It mainly spreads through infected blood transfusion or
through contaminated needles and syringes.
- It can spread through body secretions.
- It can also spread through sexual contact with the
- Main symptoms: Similar to hepatitis A.
- Preventive Measures:
- Use of disposable needles and syringes.
- Checking of blood before transfusion.
- Recovery is through natural process.
- Complete bed rest is required.
- Very light and nourishing diet without oil and fat should
- Injections of gammaglobulins in
case of hepatitis A are effective.
- Hepatitis B vaccine can be taken in case of hepatitis B.
are two other forms of hepatitis which are rare. They are as
- Delta hepatitis.
- Non-A, Non-B hepatitis.
- Causative Agent: HIV (Human Immuno - Deficiency Virus)
attacks the T4 lymphocytes and gradually destroys them.
immune system of the body gradually breaks down and it becomes
susceptible to a number of life-threatening infections.
- Structure of HIV:
Mode of Spread:
- HIV is spherical in shape.
- It is enveloped by a lipid membrane that encloses two
coats of protein.
- The inner protein coat contains a single st rand of RNA and an enzyme called Reverse
- Through sexual contact.
- Through infected blood transfusion.
- Through contaminated needles and syringes.
- From infected mother to her foetus.
- Rapid loss in weight by more than 10%.
- Prolonged fever for more than a month.
- Unexplained chronic diarrhoea.
- Swollen lymph glands.
- Night sweats.
- Main Tests Used for Diagnosis:
- Elisa test.
- Western Blot test.
- Avoid unprotected sex with the infected person.
- Avoid sex with multiple partners or a person having
- Blood should be screened properly before transfusion.
- HIV infected mothers should avoid pregnancy.
- AIDS is a fatal disease.
- No vaccine has been developed so far.
- Drugs like Zidovudine and Ribavarine are found to be effective to a
- Causative agent: Mycobacterium Leprae.
- Mode of Spread:
- Through close physical contact with the infected person.
- Air-borne infection through sneezing, coughing or spitting
from infected person.
- Through insect vectors.
- Tyberculoid leprosy.
- Lepromatous leprosy.
- Main Characteristics of Tuberculoid
- Non-infectious, few patches appear on the skin.
- Patient has high resistance against this infection.
- Generally does not produce any deformity.
- Main Characteristics of Lepromatous
- Infectious, many patches appear on the skin.
- Patient has low resistance against this infection.
- Deformities develop.
- Early detection and proper treatment.
- Isolation of patients during treatment.
- Maintaining proper hygienic conditions during treatment.
- Role of mass media in educating people.
- Drugs like Dapsone, Rifampicin and Clofazimine
are used for treatment.
may be defined as an uncontrolled and abnormal growth of cells which
- Tumors can be of the following Two Types:
- Benign or non-malignant - Mass of cells enclosed in a connective tissue
- Cancerous or malignant - Non-capsulated mass of cancerous cells.
- Cancer can be of the following four types:
- Carcinomas - Cancers of skin and breast, produced by
- Sarcomas - Cancers of bone and muscles, produced by mesodermal cells.
- Lymphomas - Caused due to abnormal production of
- Leukemias - Caused by abnormal
production of leucolytes. Example: Blood
- Characteristics of Cancer Producing Cells:
- Cancer cells grow in an abnormal and uncontrolled manner.
- They do not undergo differentiation.
- They have the capacity to travel through blood and lymph
to form secondary tumors - Metastasis.
- Excessive smoking or chewing of tobacco.
- Long exposure to X-rays, ultraviolet rays, radioactive
- Chemicals like polycyclic hydrocarbons, benzene drugs,
- Certain viruses. For example, HIV infection can lead to Kaposis sarcoma.
- Main Symptoms of Cancer:
cancer does not produce severe symptoms in early stages.
However, there are some warning signals which should be noted:
- A lump or hand mass in breast or in any other body part.
- Change in colour or size of
warts or moles on the skin.
- Unusual and excessive bleeding during menstrual periods in
- Persistent hoarseness of voice, cough and fever.
- Sores in mouth which do not heal.
- Avoid smoking and excessive drinking of alcohol.
- Avoid continuous exposure to UV rays, X-rays, etc.
- Check the quality of food, chemicals, cosmetics, etc.
diagnosed early, cancer can be treated by:
- Radiation therapy
- Combination therapy