The document discusses the classification of diseases. It begins by defining what a disease is and describing the main types. The most widely used system for classifying diseases is the World Health Organization's International Classification of Diseases (ICD). The ICD uses codes to map diseases and health conditions into broad diagnostic categories. It has gone through several revisions over time to ICD-10 to reflect advances in healthcare. The ICD classification system is used globally to facilitate disease tracking, epidemiology research, and clinical care.
2. INTRODUCTION
• A disease is a particular abnormal condition that affects part or all of an organism not caused by
external force (injury).
• The study of disease is called pathology, which includes the study of cause.
• Disease is often construed as a medical condition associated with specific symptoms and signs. It
may be caused by external factors such as pathogens or by internal dysfunctions, particularly of
the immune system, such as an immunodeficiency, or by a hypersensitivity,
including allergies and autoimmunity.
• There are four main types of disease:
• infectious diseases
• deficiency diseases
• genetic diseases (both hereditary and non-hereditary)
• physiological diseases.
• Diseases can also be classified as communicable and non-communicable.
3. CLASSIFICATION
• Diseases may be classified by cause, pathogenesis or by symptom(s).
• Alternatively, diseases may be classified according to the organ system involved, though this is
often complicated since many diseases affect more than one organ.
• A chief difficulty in nosology is that diseases often cannot be defined and classified clearly,
especially when cause or pathogenesis are unknown. Thus diagnostic terms often only reflect a
symptom or set of symptoms (syndrome).
• Classical classification of human disease derives from observational correlation between
pathological analysis and clinical syndromes. Today it is preferred to classify them by their cause if
it is known.
• The most known and used classification of diseases is the World Health Organization's ICD
(International Statistical Classification of Diseases and Related Health Problems). This is
periodically updated.
• Currently the last publication is the ICD-10, The code set allows more than 14,400 different codes
and permits the tracking of many new diagnoses. The codes can be expanded to over 16,000 codes
by using optional sub-classifications.
4. ICD
• The International Classification of Diseases (ICD) is the international "standard diagnostic tool
for epidemiology, health management and clinical purposes".
• Its full official name is International Statistical Classification of Diseases and Related Health
Problems.
• The ICD is designed as a health care classification system, providing a system of diagnostic codes
for classifying diseases, including nuanced classifications of a wide variety of signs, symptoms,
abnormal findings, complaints, social circumstances, and external causes of injury or disease. This
system is designed to map health conditions to corresponding generic categories together with
specific variations, assigning for these a designated code, up to six characters long. Thus, major
categories are designed to include a set of similar diseases.
• It contains codes for diseases, signs and symptoms, abnormal findings, complaints, social
circumstances, and external causes of injury or diseases.
• The first international classification edition, known as the International List of Causes of Death,
was adopted by the International Statistical Institute in 1893.
5. ICD
• WHO was entrusted with the ICD at its creation in 1948 and published the 6th version, ICD-6, that
incorporated morbidity for the first time. The WHO Nomenclature Regulations, adopted in 1967,
stipulated that Member States use the most current ICD revision for mortality and morbidity
statistics. The ICD has been revised and published in a series of editions to reflect advances in
health and medical science over time.
• ICD-10 was endorsed in May 1990 by the Forty-third World Health Assembly. It is cited in more
than 20,000 scientific articles and used by more than 100 countries around the world.
• The ICD is maintained by the World Health Organization (WHO), the directing and coordinating
authority for health within the United Nations System.
• Work on ICD-10 began in 1983 and was completed in 1992.
6. VERSION’S OF ICD
• The ICD - 1, published in 1900
• The ICD - 2, published in 1910
• The ICD - 3, published in 1921
• The ICD - 4, published in 1930
• The ICD - 5, published in 1939
• The ICD - 6, published in 1949
• The ICD - 7, published in 1955
• The ICD - 8, published in 1965, The ICD - 8a (adapted) published in 1968 by United States Public Health
Service.
• The ICD - 9, published in 1975
7. • International Classification of Procedures in Medicine (ICPM) was also developed (1975) and published
(1978).
• ICD - 9 - CM (clinical modification) had 3 volumes. Volumes 1 and 2 contain diagnosis codes. Volume
3 contains procedure codes for surgical, diagnostic, and therapeutic procedures created by U.S. National
Center for Health Statistics (NCHS).
• The ICD - 10, published in 1992
• ICD – 10 CM had 2 parts, ICD-10-CM, for diagnosis codes, replaces volumes 1 and 2.
• ICD-10-PCS, for procedure codes, replaces volume 3 (publishedd by NCHS in 2015)
• ICD-10-CA developed by the Canadian Institute for Health Information for morbidity classification in
Canada.
• ICD-11 (in development) A final version for approval at the WHO's WHA (World Health Assembly) is
expected in 2018.
8. Chapter Blocks Title
I A00–B99 Certain infectious and parasitic diseases
II C00–D48 Neoplasms
III D50–D89
Diseases of the blood and blood-forming
organs and certain disorders involving the
immune mechanism
IV E00–E90
Endocrine, nutritional and metabolic
diseases
V F00–F99 Mental and behavioural disorders
VI G00–G99 Diseases of the nervous system
VII H00–H59 Diseases of the eye and adnexa
9. Chapter Blocks Title
VIII H60–H95 Diseases of the ear and mastoid proces
IX I00–I99 Diseases of the circulatory system
X J00–J99 Diseases of the respiratory system
XI K00–K93 Diseases of the digestive system
XII L00–L99
Diseases of the skin and subcutaneous
tissue
XIII M00–M99
Diseases of the musculoskeletal system
and connective tissue
XIV N00–N99 Diseases of the genitourinary system
10. Chapter Blocks Title
XV O00–O99 Pregnancy, childbirth and the puerperium
XVI P00–P96 Certain conditions originating in the
XVIII R00–R99
Symptoms, signs and abnormal clinical
and laboratory findings, not elsewhere
classified
XIX S00–T98
Injury, poisoning and certain other
consequences of external causes
XX V01–Y98
External causes of morbidity and
mortality
XXI Z00–Z99
Factors influencing health status and
contact with health services
XXII U00–U99 Codes for special purposes