Linga

The term linga (rupa) means clinical features i.e., signs (chinnha), and symptoms (lakshana) of a disease.(Code: SAT-D)The clinical features of the disease are vital predictors of the severity of the underlying pathogenesis of the disease. Linga is a crucial component in understanding disease prognosis and other aspects of nidanapanchaka (five factors necessary for understanding the severity, potency, pathology, and prognosis). [Cha.Sa.Nidana Sthana 1/6]

Cardinal features are specific clinical features of a disease. Frequent defecation with variable consistency of stools (muhurbaddham muhurdravam mala) is a cardinal feature of disorders of digestion and metabolism (grahanidosha).

Linga is one of the three most essential aspects described in the Trisutra principle. [Cha.Sa.Sutra Sthana 1/24] of Ayurveda i.e., etiology (hetu), clinical features (linga), and intervention (aushadha). It is necessary for the precise knowledge and practice of Ayurvedic medicines and treatment techniques. The treatment should be prescribed only after thoroughly examining causative factors (hetu) and the signs and symptoms (lakshana) of the disease.

All systems of medicine rely primarily on the clinical features of the diseases to investigate, assess and plan the intervention accordingly. This article describes the etymology, synonyms, classification, identification methods, and importance of linga/rupa in medical practice.

Linga

Section/Chapter/topic	Concepts / Linga
Authors	Bhojani M.K.1, Tanwar Ankur kumar1
Reviewer	Basisht G.2
Editor	Deole Y.S.3
Affiliations	1 Department of Kriya Sharir, A.I.I.A., New Delhi, India, 2 Charak Samhita Research, Training and Development Centre, I.T.R.A., Jamnagar, India, 3Department of Kayachikitsa, G.J.Patel Institute of Ayurvedic Studies and Research, New Vallabh Vidyanagar, Gujarat, India
Correspondence email	carakasamhita@gmail.com, meera.samhita@aiia.gov.in
Date of first publication:	April 28, 2022
DOI	under process

Etymology and derivation

Linga is derived from the Sanskrit root "Linga" meaning "symbol" or "mark."

Synonyms

Table 1: Synonyms of linga

Charak Samhita [Cha.Sa.Nidana Sthana 1/9]	Amarkosha
Linga	Kalanka
Aakriti	Anka
Lakshana	Lanchchana
Chinnha	Lakshmana
Samsthana	Nimitta
Vyanjana	Pada
-	Pragyana

Textual meanings

• Signs and symptoms that are representations of the occurrence/existence of the disease are called rupa. [Cha.Sa.Nidana Sthana 1/9]
• The unexpressed prodromal sign and symptoms that exhibit themselves with the disease's prognosis are called rupa.[M.Ni.1/7]
• Rupa is an event or a phenomenon that describes the whole occurrence/existence of the disease even without the knowledge of the cause (hetu), aggravating/relieving factors (upashaya), and the pathogenesis (samprapti) of the disease. [Chakrapani on Cha.Sa. Nidana Sthana 1/9]
• Some of the clinical features are manifested in a disease, and some are unmanifested. As in a new born child the organs are manifested at birth but the teeth, hair, nail and other secondary sexual characters are unmanifested. Linga is described as manifested features of disease.
• Linga describes the nature (svarupa) of the disease.
• Linga serves as a base for investigations in the three methodologies of examination of the subjects i.e., interrogation (prashnapariksha), inspection (pratyakshapariksha), and inference (anumanapariksha). [Ghangadhar on Cha.Sa.Nidana Sthana 1/9]
• It is the presentation of signs and symptoms of the disease.
• It is the stage when the prodromal sign and symptoms of the disease metamorphose into the clinical features of the disease. This stage in the prognosis of the disease is indicative of the disease/pathology occurrence compared to other stages of pathogenesis that cannot be detected without investigative measures.
• Both the prodromal stage and the clinical feature of the disease don't need to have the same sign and symptoms.
• Also, not all the sign and symptoms appearing in the prodromal stage of the disease need to convert into the clinical features of the disease.
• The features that appear in/on the subject's body after the process of pathogenesis (strotodusthi and dosh-dushyasammurchana) has commenced are termed as rupa (linga).[Madhukosh commentary on M.Ni.1/7]

Classification

Three-fold classification

[Su.Sa. Nidana Sthana 1/1]

1. Dosha specific features (dosha samashraya): The sign and symptoms of the disease that arise due to interactions of dosha with dushya (dosha-dushyasammurchana) are the dosha specific features of a disease. These are often exhibited in the early stages of disease and indicative of the commencement of pathogenesis of the disease.

2. Disease-specific features (roga samashraya): The sign and symptoms experienced by the subject physically or psychologically are disease-specific features. It represents a pathological event that surpassed the subjects’ body strength and immunity (bala & ojas) and led to the occurrence of the disease.

3. Prodromal features (purvarupa): The sign and symptoms of a disease exhibited in an intermediated state of the occurrence of dosha specific and diseases specific features are called ‘Purvarupa’. These are the prodromal features that convert into the disease's cardinal features.

Two-fold classification

[Su.Sa. Nidana Sthana 1/1]:

There are two types:

1. General features (samanya rupa): These are the general clinical features of the disease. For example, feverishness (santapa) is a prevailing clinical feature of fever (jwara); loose, watery stool (atisarana) is a general clinical feature of diarrhoea (atisara).

2. Specific features (vishistha rupa): These are the special clinical features of the disease. These indicate the specificity of the pathology. It is representative of the sub-variant of a disease occurring. The clinical features of vata dominant jwara, pitta dominant jwara, kapha dominant jvara etc. are specific features.

Two-fold classification

[Su.Sa. Nidana Sthana 1/1]:

Another classification is based on the curability and severity of the disease.

1. Signs of curability (sadhyalinga)

2. Signs of incurability (asadhyalinga)

Two-fold classification

[Su.Sa.Nidana Sthana 1/1]:

 Recognized by the patient (symptoms)  Recognized by the physician (signs)

Understanding classification based on clinical applicability

1. Disease (roga) specific
2. Doshaspecific
3. Dhatu specific
4. Srotas involvement specific
5. Kriyakaala specific (stages wise)
6. Agni specific (digestive power)
7. Site-specific (organ involved specific)
8. Vega (natural urge) specific
9. Panchakarma intervention specific
10. Sama and nirama specific

Contemporary science-based classification

1. Disease-specific features
2. Disease non-specific
3. Treatment effect specific features
4. Based on adverse effects of treatment

Utility of linga in clinical practice

Importance in diagnosis

• The appearance of cardinal features of disease indicate an already occurred pathological event. In contrast, the prodromal features (purvarupa) show on going progressive pathological events.
• The appearance of signs and symptoms (linga/rupa) represents the fifth stage of disease prognosis. It is an opportunity to intervene to break the prognosis of the disease.
• Linga represents the stage of disease (vyaktavastha) where the treatment of disease (vyadhipratyanika chikitsa) can be applied directly. The practitioner keen on following such an art/mode of treatment should be well-versed in the plethora of clinical features and management. [Su.Sa. Sutra Sthana 22/34]
• Though they seem to be numerous, the signs and symptoms of the diseases are minimal and primarily similar. The permutation and combination of these clinical features and their chronology of occurrence (if mentioned in the Samprapti) that a practitioner should think about well before diagnosing disease using such an approach to treatment.
• Fatal signs or near death signs (arishta/linga/lakshana) are used to predict the sudden occurrence of the death.[M.Ni.1/2-3]

Importance in prognosis and management of the diseases

• The knowledge of the disease's clinical features (linga) is an essential component of the three fundamental elements (Trisutra) in Ayurveda. [Cha.Sa.Sutra Sthana 1/24]
• Diseases exhibiting the whole spectrum of the clinical features as mentioned in the classical books (apta) is potent and often indicative of incurability (asadhyata) or poor curability (kasthasadhyata) of the disease.
• The conversion of all prodromal features (purvarupa) into clinical features (rupa) indicates sickness progression to severity or incurability.
• In case of diseases without the prodromal sign and symptoms like vatavyadhi and kshataksheena, the practitioner has to rely on the classical features of the disease to plan the treatment module for the subject.
• Linga is an essential component of the five tools for knowledge of diseases (nidanapanchaka). [Cha.Sa.Nidhan Sthana 1/6] It is used to diagnose the stages of progression of diseases (shatkriyakala).[Su.Sa.Sutra Sthana 22/34]

Contemporary approach

• Signs are the objective evidence of disease mainly observed and interpreted by the physician rather than by the patient or lay observer. Symptoms are the subjective evidence of disease or physical disturbance observed by the patient; broadly: something that indicates the presence of a physical disorder. It is objective evidence that the patient, physician, nurse, or someone else can recognize.
• Signs indicate any abnormality, morbid phenomenon, or departure from the physician's normal structure, function, or sensation experienced, observed, and interpreted.
• The clinical features of the disease are of high diagnostic and prognostic importance. Clinical features appearing due to disease are the markers of severity and intensity of the disease. Clinical features hold critical interventional importance. The physician implements the intervention based on the severity of signs and symptoms. The asymptomatic stage of disease (no signs and symptoms) requires investigative assessments of various biological fluids (i.e., blood, urine, semen, sputum, stool, cerebrospinal fluid etc.) for diagnosis.
• Contemporary medical science relies on the clinical features for incurring precise diagnosis and planning the treatment protocols against the diseases.

Method of identification of linga

Different sorts of examinations were stated in Ayurveda for disease and patient examinations and for planning correct therapy based on prakriti, vaya, and other factors. The method of identification of clinical features in Ayurveda is trividha pariksha.

Trividhapariksha Threefold examination for assessment of linga are:

[A.Hr. Sutra Sthana. 1/22]

• Darshana: Assessment through seeing or observation.
• Saparshana: Assessment through touch.
• Prashana: Questioning or interrogation

Modern method of assessment of linga:

• History taking/Questioning
• Inspection
• Palpitation
• Percussion
• Auscultation.

Applicability of concept of linga (rupa)

• The use of Ayurvedic concepts in modern scientific techniques such as proteomics, genomics, and technology is required to develop inexpensive and cost-effective healthcare solutions. It will be based on a blend of Ayurveda and modern scientific understanding. Ayurveda's Trisutra concept [Cha.Sa.Sutra Sthana 1/24] is the foundation for a predictive, personalized, and preventative approach to maintaining good health and management of the disease. The predictive (understanding of the future disease), personalized (individual-specific variability), preventive (utilization of the concept of dietary and lifestyle modification), and promotive (enhancement of the health) medicine, along with understanding the basic physiology and pathology is the key area of concept of linga (rupa/lakshana/clinical Features) applicability.
• From a research perspective, the concept of linga plays a crucial role in finalizing the diagnosis criterion for different groups in the study. It is also used to determine the inclusion and exclusion criteria of the study. In this contemporary era, where every science depends mainly on the evidence-based approach toward treatment and maximized use of diagnostic investigations, linga (clinical features) still play a prime role of key importance in the diagnosis and management of the disease.

Current Researches

Understanding evident fatal signs (arishta lakshana): For illness diagnosis and management, every science is dependent on the linga of the condition. Because there was no accessible instrument or diagnostic test in ancient times, the physician had to analyze, observe the linga, and finally conclude the diagnosis. The arishta lakshana can be linked to modern-day death signals [Cha.Sa.Indriya Sthana]. Murmure Rasika B et al. elaborated the concept of death signs mentioned in Charak Samhita with the impending indicators just before death and up to six months before death.

Validation of tool of dhatu samyalakshana: In Ayurveda, the signs of equilibrium of body tissues (dhatu samya) can determine physical and mental well-being. T. Mahesh Raju, B et al. researched 250 seemingly healthy participants to develop, validate, and standardize a questionnaire to measure improvement in health status using Ayurvedic parameters. The final questionnaire measures health state according to Ayurvedic principles of dhatu samyata.

Cardinal features (pratyatma lakshana): A diagnostic pathological report: The distinctive and peculiar clinical features of an illness are cardinal features. Mahamad Yunus S et al. concentrated on gaining a scientific grasp of cardinal features (pratyatma lakshana)'s distinctiveness and role as a diagnostic pathological report.

Understanding proper oleation: An open-label clinical study studied the internal administration of ghee (snehapana). It was carried out on 30 psoriasis patients to evaluate the signs of proper oleation (samyaksnigdhalakshana) using a variety of clinical and biochemical markers. The study found that there were no significant changes in blood parameters. Substantial feces alterations in the presence of fat globules after snehapana were observed.

Research thesis

1. Sharma K. Sadashiv (1958): Samprapti – Lakshanyoh Sambandhah. Department of Kayachikitsa and Panchakarma, I.P.G.T.& R.A., Gujarat.
2. Reddy B.P.S. (1961): Panchanidana men upashaya. Department of Kayachikitsa and Panchakarma, I.P.G.T.& R.A., Gujarat.
3. Grover Suman (1962): Lakshansammuchchatyavimarsha. Department of Kayachikitsa and Panchakarma, I.P.G.T.& R.A., Gujarat.
4. Sharma K.M. (1962): Lakshanavimarsha(kaphajalakshanavishishitavimarshasahita. Department of Kayachikitsa and Panchakarma, I.P.G.T. & R.A., Gujarat.
5. Mishra D.D. (1963): Pitta ki UshnaGunatah SantapaLakshana Vimarsha. Department of Kayachikitsa and Panchakarma, I.P.G.T. & R.A., Gujarat.
6. Tewari Jagdish (1963): KasaRoga evam lakshana vimarsha. Department of Kayachikitsa and Panchakarma, I.P.G.T. & R.A., Gujarat.

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