Signs and symptoms
Signs and symptoms are the observed or detectable signs, and experienced symptoms of an illness, injury, or condition. A sign for example may be a higher or lower temperature than normal, raised or lowered blood pressure or an abnormality showing on a medical scan. A symptom is something out of the ordinary that is experienced by an individual such as feeling feverish, a headache or other pain or pains in the body.
A medical sign is an objective indication of a disease, injury, or abnormal physiological state that may be detected during a physical examination. These signs are visible or otherwise detectable such as a rash or bruise. Medical signs assist in arriving at an accurate diagnosis. Examples of signs include elevated blood pressure, nail clubbing of the fingernails or toenails, staggering gait, and arcus senilis and arcus juvenilis of the eyes. A sign is distinguished from an indication which is a specific reason for using a particular treatment. A symptom is something felt or experienced, such as pain or dizziness. Signs and symptoms are not mutually exclusive, for example a subjective feeling of fever can be noted as sign by using a thermometer that registers a high reading.
Signs and symptoms are often non-specific, but some combinations can be suggestive of certain diagnoses, helping to narrow down what may be wrong. A particular set of characteristic signs and symptoms that may be associated with a disorder is known as a syndrome. In cases where the underlying cause is known the syndrome is named as for example Down syndrome and Noonan syndrome. Other syndromes such as acute coronary syndrome may have a number of possible causes.
In other cases when known as cardinal signs and symptoms they are specific even to the point of being pathognomonic. A cardinal sign or cardinal symptom can also refer to the major sign or symptom of a disease. Abnormal reflexes can indicate problems with the nervous system. Signs and symptoms are also applied to physiological states outside the context of disease, as for example when referring to the signs and symptoms of pregnancy, or the symptoms of dehydration.
Signs versus symptoms
Signs are different from experienced symptoms. A sign of a disorder is something that may be observed by another or detected during a medical examination or procedure. For example high blood pressure may be noted as a sign during an examination for which there have been no reported symptoms. A symptom is something experienced and reportable by a person such as a headache or fatigue. Signs and symptoms may overlap, such as a bloody nose, which the individual experiences as unusual (symptom) and which others observe (sign).
Signs and symptoms may be mild or severe, brief or longer-lasting when they may become reduced (remission), or then recur (relapse or recrudescence) known as a flare-up. A flare-up may show more severe symptoms.
The term chief complaint, also "presenting problem", is used to describe the initial concern of an individual when seeking medical help, and once this is clearly noted a history of the present illness may be taken. The symptom that ultimately leads to a diagnosis is called a cardinal symptom.
Constitutional symptoms are very general and non-specific that can be associated with a wide range of conditions. They include weight loss, headache, pain, fatigue, loss of appetite, night sweats, and malaise. A constitutional symptom may be primary or secondary.
Vital signs are the four signs that can give an immediate measurement of the body”s overall functioning and health status. They are temperature, heart rate, breathing rate, and blood pressure. The ranges of these measurements vary with age, weight, gender and with general health.
A digital application has been developed for use in clinical settings that measures three of the vital signs (not temperature) using just a smartphone, and has been approved by NHS England. The application is registered as Lifelight First, and Lifelight Home is under development (2020) for monitoring-use by people at home using just the camera on their smartphone or tablet. This will additionally measure oxygen saturation and atrial fibrillation. Other devices are then not needed.
Many conditions are indicated by a group of known signs, or signs and symptoms. These can be a group of three known as a triad; a group of four known as a tetrad, and a group of five known as a petrad. An example of a triad is Meltzer's triad presenting purpura a rash, arthralgia painful joints, and myalgia painful and weak muscles. Meltzer's triad indicates the condition cryoglobulinemia. Huntington's disease is a neurodegenerative disease that is characterized by a triad of motor, cognitive, and psychiatric signs and symptoms. A large number of these groups that can be characteristic of a particular disease are known as a syndrome. Noonan syndrome for example, has a diagnostic set of unique facial and musculoskeletal features.
Positive and negative
Sensory symptoms can also be described as positive symptoms, or as negative symptoms depending on whether the symptom is abnormally present such as tingling or itchiness, or abnormally absent such as loss of smell. The following terms are used for negative symptoms – hypoesthesia is a partial loss of sensitivity to moderate stimuli, such as pressure, touch, warmth, cold. Anesthesia is the complete loss of sensitivity to stronger stimuli, such as pinprick. Hypoalgesia (analgesia) is loss of sensation to painful stimuli. Symptoms are also grouped in to negative and positive for some mental disorders such as schizophrenia. Positive symptoms are those that are present in the disorder and are not normally experienced by most individuals and reflects an excess or distortion of normal functions. Examples are hallucinations, delusions, and bizarre behavior. Negative symptoms are functions that are normally found but that are diminished or absent such as apathy and anhedonia.
Radiologic signs are abnormal findings on imaging scanning. These include the Mickey Mouse sign and the Golden S sign. When using imaging to find the cause of a complaint, another unrelated finding may be found known as an incidental finding.
Cardinal signs and symptoms are those that may be diagnostic, and pathognomonic – of a certainty of diagnosis. Inflammation for example has a recognised group of cardinal signs and symptoms, as does exacerbations of chronic bronchitis, and Parkinson's disease.
In contrast to a pathognomonic cardinal sign, the absence of a sign or symptom can often rule out a condition. This is known by the Latin term sine qua non. For example the absence of known genetic mutations specific for a hereditary disease would rule out that disease. Another example is where the vaginal pH is less than 4.5, a diagnosis of bacterial vaginosis would be excluded.
A reflex is an automatic response in the body to a stimulus. Its absence, reduced (hypoactive), or exaggerated (hyperactive) response can be a sign of damage to the central nervous system or peripheral nervous system. In the patellar reflex (knee-jerk) for example, its reduction or absence is known as Westphal's sign and may indicate damage to lower motor neurons. When the response is exaggerated damage to the upper motor neurons may be indicated.
A number of medical conditions are associated with a distinctive facial expression or appearance known as a facies An example is elfin facies which has facial features like those of the elf, and this may be associated with Williams syndrome, or Donohue syndrome. The most well-known facies is probably the Hippocratic facies that is seen on a person as they near death.
A symptom (from Greek σύμπτωμα, "accident, misfortune, that which befalls", from συμπίπτω, "I befall", from συν- "together, with" and πίπτω, "I fall") is a departure from normal function or feeling. Symptomatology (also called semiology) is a branch of medicine dealing with the signs and symptoms of a disease. This study also includes the indications of a disease. It was first described as semiotics by Henry Stubbe in 1670 a term now used for the study of sign communication.
Prior to the nineteenth century there was little difference in the powers of observation between physician and patient. Most medical practice was conducted as a co-operative interaction between the physician and patient; this was gradually replaced by a "monolithic consensus of opinion imposed from within the community of medical investigators". Whilst each noticed much the same things, the physician had a more informed interpretation of those things: "the physicians knew what the findings meant and the layman did not".:82
Development of medical testing
A number of advances introduced mostly in the 19th century, allowed for more objective assessment by the physician in search of a diagnosis, and less need of input from the patient. During the 20th century the introduction of a wide range of imaging techniques have made a huge impact on diagnostic capability. Other developments in the field of genetics, medical biochemistry, and molecular diagnostics have also played major roles.
- In 1761 the percussion technique for diagnosing respiratory conditions was discovered by Leopold Auenbrugger. This method of tapping body cavities to note any abnormal sounds had already been in practice for a long time in cardiology. Percussion of the thorax became more widely known after 1808 with the translation of Auenbrugger's work from Latin into French by Jean-Nicolas Corvisart.
- In 1819 the introduction of the stethoscope by René Laennec began to replace the centuries old technique of immediate auscultation – listening to the heart by placing the ear directly on the chest, with mediate auscultation using the stethoscope to listen to the sounds of the heart and respiratory tract. Laennec's publication was translated into English, 1821–1834, by John Forbes
- The 1846 introduction by surgeon John Hutchinson (1811–1861) of the spirometer, an apparatus for assessing the mechanical properties of the lungs via measurements of forced exhalation and forced inhalation. (The recorded lung volumes and air flow rates are used to distinguish between restrictive disease (in which the lung volumes are decreased: e.g., cystic fibrosis) and obstructive diseases (in which the lung volume is normal but the air flow rate is impeded; e.g., emphysema).)
- The 1851 invention by Hermann von Helmholtz (1821–1894) of the ophthalmoscope, which allowed physicians to examine the inside of the human eye.
- The (c. 1870) immediate widespread clinical use of Sir Thomas Clifford Allbutt's (1836–1925) six-inch (rather than twelve-inch) pocket clinical thermometer, which he had devised in 1867.
- The 1882 introduction of bacterial cultures by Robert Koch, initially for tuberculosis, being the first laboratory test to confirm bacterial infections.
- The 1895 clinical use of X-rays which began almost immediately after they had been discovered that year by Wilhelm Conrad Röntgen (1845–1923).
- The 1896 introduction of the sphygmomanometer, designed by Scipione Riva-Rocci (1863–1937), to measure blood pressure.
The recognition of signs, and noting of symptoms may lead to a diagnosis. Otherwise a physical examination may be carried out, and a medical history taken. Further diagnostic medical tests such as blood tests, scans, and biopsies, may be needed. An X-ray for example would soon be diagnostic or not of a bone fracture.
Examples of signs
- "Beyond Intuition: Quantifying and Understanding the Signs and Symptoms of Fever". clinicaltrials.gov. 5 October 2017. Retrieved 9 January 2021.
- "Symptoms and self-help guides by body part | NHS inform". www.nhsinform.scot. Retrieved 9 January 2021.
- "Definition of SIGN". www.merriam-webster.com.
- Marie T. O'Toole, ed., Mosby's Medical Dictionary, 9th ed. (St. Louis, MO: Elsevier/Mosby, 2013), Kindle loc. 154641. ISBN 9780323085410
- Basu, S; Sahi, PK (July 2017). "Malaria: An Update". Indian journal of pediatrics. 84 (7): 521–528. doi:10.1007/s12098-017-2332-2. PMID 28357581.
- "Measles Signs and Symptoms". Centers for Disease Control and Prevention. 5 November 2020. Retrieved 31 December 2020.
- Shiel, William C. Jr. (20 June 2019). "Definition of Flare". MedicineNet. Retrieved 21 December 2019.
- "Solution". Lifelight. Retrieved 2 February 2021.
- Jensen RN, Bolwig T, Sørensen SA (March 2018). "[Psychiatric symptoms in patients with Huntington's disease]". Ugeskr Laeger (in Danish). 180 (13). PMID 29587954.
- "Noonan syndrome: MedlinePlus Genetics". medlineplus.gov. Retrieved 2 February 2021.
- Harrison's Principles of Internal Medicine, 19th edition, Chapter 31: Numbness, Tingling, and Sensory Loss
- "Mental Health: a Report from the Surgeon General". Surgeongeneral.gov. 1999. Archived from the original on 11 January 2012. Retrieved 17 December 2011.
- Understanding Psychosis Archived 2012-12-25 at the Wayback Machine, Mental Health Illness of Australia.
- Freire, MO; Van Dyke, TE (October 2013). "Natural resolution of inflammation". Periodontology 2000. 63 (1): 149–64. doi:10.1111/prd.12034. PMC 4022040. PMID 23931059.
- Archived 2006-04-06 at the Wayback Machine
- Lynch HT, Lynch JF, Lynch PM, Attard T (2008). "Hereditary colorectal cancer syndromes: molecular genetics, genetic counseling, diagnosis and management". Fam Cancer. 7 (1): 27–39. doi:10.1007/s10689-007-9165-5. PMID 17999161.
- Mańka W, Adrianowicz L, Wesołek Z, Adrianowicz K (2002). "[The value of determining vaginal secretion reaction (pH) as a screening test of bacterial vaginosis]". Wiad Lek (in Polish). 55 (1–2): 51–5. PMID 12043316.
- "Definition of REFLEX". www.merriam-webster.com.
- "Definition of FACIES". www.merriam-webster.com. Retrieved 4 February 2021.
- Chadwick, J. & Mann, W.N.(trans.) (1978). Hippocratic writings. Harmondsworth, UK: Penguin. pp. 170–71. ISBN 0-14-044451-3.CS1 maint: multiple names: authors list (link)
- King, Lester S. (1982). Medical Thinking: A Historical Preface. Princeton, NJ: Princeton University Press. ISBN 0-691-08297-9.
- "Sumptoma, Henry George Liddell, Robert Scott, A Greek-English Lexicon, at Pursues". Perseus.tufts.edu. Retrieved 17 December 2011.
- The British Medical Association (BMA) (2002). Illustrated Medical Dictionary. A Dorling Kindersley Book. p. 406. ISBN 978-0-75-133383-1.
- "Definition of SYMPTOMATOLOGY". www.merriam-webster.com. Retrieved 9 January 2021.
- "Definition of SEMIOLOGY". www.merriam-webster.com. Retrieved 9 January 2021.
- David A. Bedworth, Albert E. Bedworth (2010). The Dictionary of Health Education. Oxford University Press. p. 484. ISBN 978-0-19-534259-8. Archived from the original on 9 May 2018.
- Jewson, N.D., "Medical Knowledge and the Patronage System in 18th Century England Archived 7 March 2009 at the Wayback Machine", Sociology, Vol. 8, No. 3 (1974), pp. 369–85.
- Jewson, N.D., "The Disappearance of the Sick Man from Medical Cosmology, 1770–1870 Archived 16 March 2009 at the Wayback Machine", Sociology, Vol. 10, No. 2, (1976), pp. 225–44.
- Tsouyopoulos N (1988). "The mind-body problem in medicine (the crisis of medical anthropology and its historical preconditions)". Hist Philos Life Sci. 10 Suppl: 55–74. PMID 3413276.
- Bedford DE (November 1971). "Auenbrugger's contribution to cardiology. History of percussion of the heart". Br Heart J. 33 (6): 817–21. doi:10.1136/hrt.33.6.817. PMC 458433. PMID 4256273.
- Allbutt, T.C., "Medical Thermometry", British and Foreign Medico-Chirurgical Review, Vol. 45, No. 90, (April 1870), pp. 429–41; Vol. 46, No. 91, (July 1870), pp. 144–56.