A disease is a condition that impairs the proper function of the body or of one of its parts. Every living thing, both plants and animals, can succumb to disease. Hundreds of different diseases exist.
Each has its own particular set of symptoms and signs, clues that enable a physician to diagnose the problem. A symptom is something a patient can detect, such as fever, bleeding, or pain. A sign is something a doctor can detect, such as a swollen blood vessel or an enlarged internal body organ.
Every disease has a cause, although the accuses of some remain to be discovered. Every disease also displays a cycle of onset, or beginning, course, or time span of affection, and end, when it disappears or it partially disables or kills its victim. An epidemic diseases one that strikes many persons in a community. When it strikes the same region year after year it is an endemic disease. An acute disease has a quick onset and runs a short course. A chronic disease has a slow onset and runs a sometimes years-long course. The gradual onset and long course of rheumatic fever makes it a chronic ailment.
Kinds of Disease
Infectious, or communicable, diseases are those that can be passed between persons such as by means of airborne droplets from a cough or sneeze. Tiny organisms such as viruses, bacteria, fungi and worms can produce infectious diseases. Whatever the causative agent, it services in the person it infects and is passed on to another. Sometimes, a disease-producing organism gets into a person who shows no symptoms of the disease. The asymptomatic career can then pass the disease on to someone else without even knowing he has it.
Non-infectious, or non-communicable diseases are caused b malfunctions of the body. These include organ or tissue degeneration, erratic cell growth, and faulty blood formation and flow. Also included are disturbances of the stomach and intestine, the endocrine system, and the urinary and reproductive systems. Some diseases are be caused by diet deficiencies, lapses in the body’s defense system, or a poorly operating nervous system.
Deficiency diseases are due to deficiency in the diet of a nutrient. They can generally be cured by providing the missing nutrients. (a) Protein deficiently causes two major diseases kwashiorkor and Marasmus. (b) Mineral deficiency causes specific diseases. (i) Anaemia : Iron deficiency causes hemoglobin deficiency in blood. (ii) Goitre : iodine deficiency causing no synthesis of thyrozine hormone of thyroid gland). (iii) Hypokalemia : (potassium deficiency). (iv) Hyponatremia : (sodium causes this state of low blood pressure and loss of body weight. (c) Vitamin deficiency causes a variety of disease. (i) Night Blindness: (Vitamin A). (iv) Beri-beri: (Vitamin B0thiamine). (v) Ariboflavinosis : (Vitamin B0riboflavin) (vi) Pellagra: (nicotinic acid / niacin-part of B complex group). (vii) Pemicious Anaemia: (Vitamin C – ascorbic acid). (ix) Rickets : (a disease causing disorder of calcium and phosphorus metabolism due to Vitamin D deficiency, often found in the early childhood: 60 months and 2 years. (x) Ostemalacia: (Vitamin D)
Infectious disease are caued by various agents such as virus, bacteria, fungi and protozoa. (a) Disease caused by Bacteria : Cholera, Diphtheria, Tuberculosis, Leprosy, Tetanus, Typhoid, Plague, Whooping Cough, Sore Throat, Pneumonia, Bacillar Dysentery, Gonorrhea, Syphilis and Botulism. (b) Diseases caused by Viruses : Chickenpox, Measles, Poliomyelitis, Rabies, Mumphs, Influenza, Hepatitis, Herpes, Viral Encephalitis and AIDS. (c) Diseases caused by Fungi : Ringworm, Athelet’s fott, Dhobie itch. (D) Diseases caused by protozoans: Amoebiasis, Malaria, Sleeping sickness, Kalaazar, Diarrhoea, (e) Diseases caused by Helminthes or Worms: Filaria, Tapeworm and Hookworm transmission.
Degenerative disease occur due to malfunctioning of some organ or organ system in the body. They are Hear Attack, Diabetes mellitus, Arthritis.