According to Tamil literature, Siddham means mind. Siddha means achievements with perfection. Those who attained an intellectual level of perfection were called as Siddhars . Most of the diseases are related to mind. The primitive cause of the disease is the variation and disturbance in mind. Thus, we have to treat the mind to cure the physical problem. So Siddhars stressed the value of leading calm, peaceful life with the help of yoga, pranayama etc. By this fact, one can understand that Siddha not only deals with the physical illness, but also with the mental illness.

Universe is the macrocosam and the human being is the microcosm. What are all present in the macrocosm present in the human body (microcosm) also. The primordial five elements of panchabootham are the compounds of anything found in nature. Man is constant interacting with coamos. When these are disturbance to this rhythum it manifests into disease.

Body is composed of five elements, the substance and function is maintained by food which also contain the panchabhudas as their compounds of the basic principle of Siddha is “Unave marunthu, Maruthae unavu” . That is food is medicine, medicine is food, which means by taking the proper diet one can protect once body from all ailment, and also at the time of any diseases by regulating the dietary habits one can get rid of the diseases.

1. Vadham

2. Vaidhyam

3. Yogam

4. Gnanam

Siddhars primitive aim is to attain the eternity. To attain this, living a healthy life is very important. Thus the aim is to lead a life without any disease and to promote the health.

Healthy body with a healthy mind is the definition of health in Siddha.

In Siddha diagnosis is based on reading of pulse. One can understand this by Noi naadi noi mudhal naadi athu thanikkum Vaai naadai vaaiyppa cheyal ….By assessing the pulse one can easily diagnose the nature of disease, even if the patient is in the sate of unconscious. In the pulse the three important classifications are there i.e.  Vali (Vaatham), Azhal (Pitham), Iyam (Kabam) – (Mikinum kuraiyinum noiseyyum noolor Vali muthaai enniya moontru – Thirukkural) with specific measurements. By the variation of the pulse, one can differentiate the diseases. And here Envaigaithervu is also essential. By the eight diagnosing methods one can easily arrive of the diagnosis of the disease.

The Mukkutram are Vali (Vaatham), Azhal (Pitham), Iyyam (Kabam). These are the composition of the any two Panchabootham . In a normal person the Mukkutram must be in perfect balance. Each Kutram possess its original character. These three Kutram s are also influenced by the nature of food, nature of place where the persons live, season, climate, mental health.. etc. Persons may be single Kutram or combination of two Kutram depending upon this one can assess the constitution of the individual .

One can easily understand that the Mukkutram function by the following stanza

“Vaathamai padaithu,
Pithamvanniyaai kaathu,
Silethuma seethamaai thudaithu” (Theran)
By this one can understand vaatham helps in Inception, Pitham helps in preservation and Kabam helps in demolition.

Vaatham is production. It is responsible for the production / implementation of thoughts to action. Generally, its function is more related to cerebral activities like, thinking and action. There are 10 classification in  vaatham.

Pitham is for preserving the body. It is responsible for the normal metabolism. It controls the digestion, the level of haemoglobin [ayachenthavalam], the movement of limbs, the function of eyes to enhance vision, the complexion of skin and the sharpness of the mind etc.

Kabam's function is destructive in nature. It can be understand by the term “Silethuma seethumai thudaitthu” According to Siddha principle in old age the cause of death is by Kabam . There are 5 classifications in Kabam

Diet [Unavu murai] and mind are mainly affecting the health. According to great Siddhar Thiruvalluvar “M arunthena vendaavaam yaakkaikku arunthiyadhu atrathu potri unnin”

Siddha treatment is basically not only curing the diseases but also prevention. According to Siddha concept “Varumun kaappom”, that is prevention is better than cure. Since the principle aim is to achieve the eternity. It also helps in longevity through Kaayakalpam, that is rejuvenator

If the Mukkutram are not in normal range, that is the sign of the disease. To keep the Mukkutram to normal, we can follow the following principles.

“Viresanathaal vaathan thaalum,
Vamanathaal Pithamn thaalum,
Nasiya anjanathaal Kabam thaalum thaane”
It means Vaatham is balanced by purgation, Pitham is balanced by emesis and Kabam is balanced by Nasal Insufflations with liquids and by applying medicine in the eye.

These are corresponding to the nerve plexuses of the body. They are

ABANAN: This corresponds to the pelvic plexus.
Function : It's main function is to control the excretory function.

SAMANAN: This corresponds to solar plexus in the navel region.
Function : It's main function is to control the digestive system.

PRANAN: This corresponds to cardiac plexus in the heart region.
Function : This is responsible for the circulation, breathing and biocombustion of nutrients

UDHANAN: This corresponds to the plexus in the throat region, that is pharyngeal plexus.
Function : It is responsible for the speech, swallowing, breathing, conduction of food, etc

VIYANAN: This corresponds to the naso ciliary plexus at the root of the nose and the base of skull which spreads allover to the body.
Function : It is responsible for the movement of the body and the nutrition of the thathus

They are

ANALA PITHAM: It denotes inherent heat in the stomach
FUNCTION : This gives appetite and it is responsible for digestion

PRASAGA PITHAM: It denotes the colour pigments of the skin
FUNCTION : This is responsible for the complexion of the skin.

RANJAHA PITHAM: It denotes the haemoglobin
FUNCTION : This is responsible for the colour of blood.

AALOSAHA PITHAM: It denotes the aqueous humour
FUNCTION : This is responsible for the maintenance of vision.

SAATHAAGA PITHAM: It denotes the life energy.
FUNCTION : This activates the whole body.

The five types of Kabam are as follows

KILATHAGAM: It denotes the saliva
FUNCTION : It is secreted by the three pairs of salivary glands, which is useful in mastication.

THARPAGAM: This is cerebrospinal fluid.
FUNCTION : This is responsible for the protection of cerebrum.

POTHAGAM: It denotes the lymph
FUNCTION : This is responsible for the immunity, absorption of excess fluid and return to the blood stream.

SANTHIGAM: It denotes the synovial fliud.
FUNCTION : This is responsible for the lubrication and free movement of joints.

The classification of medicine in Siddha medicine is divided into 64 types. It is further classified into two types, that is 32 types of internal medicine and 32 types of external medicine based on the administration of medicine.

32 types of Internal Medicine in Siddha.