Disease

A disease is an abnormal condition or impairment of the body of an organism, including any of its organs, systems, or parts, and that has a specific cause and characteristic signs or symptoms. Diseases cause discomfort, dysfunction, or distress to the organism afflicted or those in contact with the organism. In humans, disease can also refer to an abnormal condition of the mind. Disease may be due to such factors as genetic defect, infection, diet, physical or mental stress, the environment, or a combination of these factors.

Sometimes the term disease is used broadly to include injuries, disabilities, syndromes, symptoms, infections, deviant behaviors, and atypical variations of structure and function, while in other contexts these may be considered distinguishable categories.

The term disease is often used metaphorically for disordered, dysfunctional, or distressing conditions of other things, as in disease of society.

In contrast to the medical model, many healing arts such as acupuncture seek to treat the whole person by seeking to find balance and wholeness that ends disease with little concern for western signs or symptoms.

Pathology is the study of diseases. The subject of systematic classification of diseases is referred to as nosology. The broader body of knowledge about human diseases and their treatments is medicine. The study of diseases affecting domestic animals, wildlife, and exotic and production animals is veterinary medicine. Plants as well can suffer from a variety of processes such as infection, nutrient deficiency, or deleterious mutation. The study of diseases affecting plants is termed plant pathology.

Illness can be defined as a state of poor health, with health defined by the World Health Organization as "a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity" (WHO, 1946). What can cause and continue this impairment of physical, mental, or social well-being includes but is not limited to disease.

Syndromes, illness, symptoms, and signs

Medical usage sometimes distinguishes a disease, which has a known specific cause or causes (called its etiology), from a syndrome, which is a collection of signs or symptoms that occur together. However, many conditions have been identified, yet continue to be referred to as "syndromes". Furthermore, numerous conditions of unknown etiology are referred to as "diseases" in many contexts.

Illness, although often used to mean disease, can also refer to a person's perception of their health, regardless of whether they in fact have a disease. A person without any disease may feel unhealthy and believe he has an illness. Another person may feel healthy and believe he does not have an illness even though he may have a disease such as dangerously high blood pressure which may lead to a fatal heart attack or stroke.

Symptom

The term symptom (from the Greek syn = con/plus and pipto = fall, together meaning co-exist) has two similar meanings in the context of physical and mental health:

• Strictly, a symptom is a sensation or change in health function experienced by a patient. Thus, symptoms may be loosely classified as strong, mild, or weak. In this, medically correct sense of the word, it is a subjective report, as opposed to a sign, which is objective evidence of the presence of a disease or disorder. Examples of symptoms are fatigue/tiredness, pain, or nausea. The symptom that leads to a diagnosis is called a cardinal symptom. In contrast, elevated blood pressure, or abnormal appearance of the retina, would be a medical sign indicating the nature of the disease.

• A symptom may loosely be said to be a physical condition that shows that one has a particular illness or disorder (see e.g. Longman, 1995). An example of a symptom in this sense of the word would be a rash. However, correctly speaking, this is known as a sign, as would any indication detectable by a person other than the sufferer in the absence of verbal information from the patient.

Some symptoms (e.g. nausea) occur in a wide range of disease processes, whereas other symptoms are fairly specific for a narrow range of illnesses: for example, a sudden loss of sight in one eye has only a very limited number of possible causes.

Some symptoms can be misleading to the patient or the medical practitioner caring for them. For example, inflammation of the gallbladder quite often gives rise to pain in the right shoulder, which might (quite reasonably) lead the patient to attribute the pain to a non-abdominal cause such as muscle strain, rather than the real cause.

A symptom can more simply be defined as any feature that is noticed by the patient. A sign is noticed by the doctor or others. It is not necessarially the nature of the sign or symptom that defines it, but who observes it. Clearly then, the same feature may be noticed by both doctor and patient, and so is at once both a sign and a symptom. The distinction is as simple as this, and therefore it may be nonsensical to argue whether a particular feature is a sign or a symptom. It may be one, the other, or both, depending on the observer(s). Some features, such as pain, can only be symptoms. A doctor can not feel a patient's pain (unless he is the patient!). Others can only be signs, such as a blood cell count measured by a doctor in his/her laboratory.

Transmission of disease

Some diseases, such as influenza, are contagious or infectious, and can be transmitted by any of a variety of mechanisms, including coughs and sneezes, sexual transmission, by bites of insects or other carriers of the disease, from contaminated water or food, and so forth.

Other diseases, such as cancer and heart disease, are not considered to be due to infection, although microorganisms may play a role.

Social significance of disease

The identification of a condition as a disease, rather than as simply a variation of human structure or function, can have significant social or economic implications. The controversial recognitions as diseases of post-traumatic stress disorder, also known as "shell shock"; repetitive motion injury or repetitive stress injury (RSI); and Gulf War syndrome has had a number of positive and negative effects on the financial and other responsibilities of governments, corporations, and institutions towards individuals, as well as on the individuals themselves.

A condition may be considered to be a disease in some cultures or eras but not in others. Oppositional-defiant disorder, attention-deficit hyperactivity disorder, and, increasingly, obesity are conditions considered to be diseases in the United States and Canada today, but were not so-considered decades ago and are not so-considered in some other countries. Lepers were a group of afflicted individuals who were historically shunned and the term "leper" still evokes social stigma. Fear of disease can still be a widespread social phenomena, though not all diseases evoke extreme social stigma.

Disease Prevention

There are many factors that have been identified in the health promotion and wellness movements that can assist in the prevention of disease.

Some of the major ones include: good nutrition, exercise, stress management, self responsibility, wise use of medical resources, healthy environments, good human relationships, and a positive outlook on life.

A Harvard University publication on nutrition references that healthy eating can prevent 25% of all cancers and combined with exercise and being a nonsmoker can prevent up to 90% of adult onset diabetes.

Exercise has been shown to reduce risks for diseases such as heart disease, high blood pressure, diabetes, obesity, and colon cancer. In addition, exercise has been shown to also reduce risks for some mental diseases, such as depression.

Good stress management can also reduce the risk of and/or prevent disease. Stress can be a contributing or even primary factor to a number of pathologies or combination of pathologies including cardiovascular disease, mental diseases, internal organ diseases, or musculoskeletal diseases.

Self-responsibility for one’s health is also a critical way to prevent disease. The person who takes responsibility for not smoking reduces risks for several diseases such as heart disease, stroke, lung cancer, and throat cancer, to name a few. In the same, way responsible alcohol consumption can reduce the risks for cirrhosis of the liver, alcoholism, and other mental diseases. In the same manner, taking responsibility to avoid addicting drugs can prevent disease. A person taking measures for responsible sexual behavior can also help prevent or reduce risks for several diseases, including HIV-AIDS.

Wise use of medical resources includes having appropriate age related checkups to detect or catch diseases early on so they can be treated effectively. Some of the common preventive checkups include: screenings for blood pressure, cholesterol/HDL ratios, breast exams for women, and so forth.

Living in a healthy environment is becoming increasingly important to preventing disease. Access to clean water and sanitation, freedom from toxic chemical exposure, clean air, and so forth can help reduce and prevent disease.

Finally having satisfying human relationships and a positive outlook on life have been found to be a factor in the reduction and/or prevention of disease. In one study of 40,000 people performed by the U.S. Department of Health and Human Services, it was found that satisfying human relationships and job satisfaction were better predictors (inverse correlation) of heart disease than all other factors.

List of common diseases

This is a list of common, well-known or infamous diseases. This is neither complete nor authoritative. This is not intended to be a list of rare diseases, nor is it a list of mental disorders.

This list includes both common names and technical names for diseases. This is deliberate; where multiple names are in common use for the same disease, all of those names should link to the main article for the disease.

This list has been collated from various sources in the Wikipedia, and public domain resources.

• A number of rare diseases may be present in this list. Unless they are notable for other reasons (for example, Ebola), please remove rare diseases from this list, and add them to the list of rare diseases if they are not already listed there.

List of diseases (in alphabetical order):

Contents: Top - 0–9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

A

• Achondroplasia
• Acne
• Adenoma]]*
• Ageing
• AIDS
• Albinism
• Alcoholic hepatitis
• Alopecia
• Alzheimer's disease
• Amblyopia
• Amoebiasis or Amebiasis
• Anemia
• Aneurysm
• Anosmia
• Anotia
• Anthrax
• Appendicitis
• Apraxia
• Argyria
• Arteritis
• Arthritis
• Aseptic meningitis
• Asthenia
• Asthma
• Atherosclerosis
• Athetosis
• Atrophy
• Autism

B

• Bacterial meningitis
• Beriberi
• Bipolar disorder
• Botulism
• Brucellosis
• Bubonic plague

C

• Calculi
• Campylobacter infection
• Cancer
• Candidiasis
• Cardiac arrest
• Chagas disease
• Chalazion
• Chancroid
• Cherubism
• Chickenpox
• Chlamydia
• Chlamydia trachomatis
• Cholera
• Chordoma
• Chorea
• Chronic fatigue syndrome
• Cleft lip
• Coccidioidomycosis
• Colitis
• Color blindness
• Common cold
• Condyloma
• Congestive heart disease
• Coronary heart disease
• Cowpox
• Cretinism
• Cystic Fibrosis

D

• Diabetes mellitus
• Diphtheria

E

• Ebola
• Encephalitis

F

• Foodborne illness

G

• Gonorrhoea
• Glandular fever

H

• Huntington's disease
• Hypertension

I

• Ichthyosis
• Influenza
• Interstitial cystitis
• Iritis
• Iron-deficiency anemia
• Irritable bowel syndrome
• Jaundice / Hepatitis

J

• Jaundice

K

• Keloids
• Keratosis pilaris(
• Kuru
• Kwashiorkor

L

• Lazy eye
• Lead poisoning
• Legionellosis
• Leishmaniasis
• Leprosy
• Leptospirosis
• Listeriosis
• Leukemia
• Loiasis
• Lupus erythematosus
• Lyme disease
• Lymphogranuloma venereum
• Lymphoma

M

• Malaria
• Marburg fever
• Measles
• Melioidosis
• Ménière's disease
• Meningitis
• Migraine
• Multiple myeloma
• Multiple Sclerosis
• Mumps
• Muscular dystrophy
• Myasthenia gravis
• Myelitis
• Myoclonus
• Myopathy
• Myopia
• Myxedema
• Meninggococemia

N

• Neoplasm
• Non-gonococcal urethritis

O

• Obsessive-compulsive disorder
• Obesity
• Osteoarthritis

P

• Paratyphoid fever
• Parkinson's disease
• Pelvic inflammatory disease
• Peritonitis
• Periodontal disease
• Pertussis
• Phenylketonuria
• Pityriasis rosea
• Plague (bubonic, septicemic, pneumonic, and pharyngeal)
• Pneumonia
• Polio or Poliomyelitis
• Porphyria
• Progeria
• Prostatitis
• Psittacosis
• Psoriasis
• Pubic lice

Q

• Q fever

R

• Rabies
• Raynaud's disease
• Repetitive strain injury (RSI)
• Rheumatic fever
• Rheumatoid arthritis
• Rickets
• Rift Valley fever
• Rocky Mountain spotted fever
• Rubella
• Rheumatic heart disease

S

• Salmonellosis
• Scabies
• Scarlet fever
• Sciatica
• Schizophrenia
• Scleroderma
• Scrapie
• Scurvy
• Sepsis
• SARS
• Shigellosis
• Shingles
• Shock
• Sickle-cell disease
• Siderosis
• Silicosis
• Smallpox
• Stevens-Johnson syndrome
• Strabismus
• Strep throat
• Streptococcal infection
• Synovitis
• Syphilis

T

• Taeniasis
• Tay-Sachs disease
• Teratoma
• Tetanus
• Thalassaemia
• Thrush
• Thymoma
• Tinnitus
• Toxic shock syndrome
• Trichinosis
• Trichomoniasis
• Trisomy
• Tuberculosis
• Tularemia
• Tungiasis
• Typhoid or Typhoid fever
• Typhus

U

• Ulcerative colitis
• Uremia
• Urticaria
• Uveitis

V

• Varicella
• Vasovagal syncope
• Vitiligo
• Von Hippel-Lindau disease

W

• Warkany syndrome
• Warts
• Whooping cough (Pertussis)

Y

• Yellow fever
• Yaws

References

ISBN links support NWE through referral fees

• Harvard Medical School. 2006. Healthy Eating: A guide to the new nutrition. A Special Report of the Harvard Medical School. http://www.health.harvard.edu/special_health_reports/Healthy_Eating.htm (accessed July 2, 2006).
• World Health Organization (WHO). 1946. Constitution of the World Health Organization. http://w3.whosea.org/aboutsearo/pdf/const.pdf.

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