Hetu (Causative
Factors)
They are the factors or causes that lead to the disease causing pathology.
These Hetu can be internal (nija) and external (agantu) and are capable of
disturbing the balance of three doshas (i.e. Vata, pitta and kapha).
In ayurveda Hetu has been classified into different branches that are as
follows:
1a) Sannikrisht (close factor)
These are the factors that bypass the sanchay stage of the disease process
to the next stage of disease process i.e. prakopa (provocation) by
disturbing the equilibrium of the three doshas (vata, pitta, kapha) by the
three following factors:
- Stages of the day (morning, afternoon, evening)
- Stages of night (early night, mid night, late night)
- Stages of digestion (amawasth, pachyamanawastha, pakwastha) An
illustrating example of such a disease is trauma (Sannikrisht).
1b) Viprikrisht (distant factor)
These are the factors that effect the equilibrium of doshas, which was
developed earlier but was unable to develop disease. In this case as the
disturbed equilibrium of dosha (sanchay) already exists the onset of the
ailment is quick due to other stimulating factors.
An illustrating example is: during shishirarutu (winter) season equilibrium
of kapha dosha is disturbed but it doesn't lead to disease as it is frozen
due to extreme cold but as soon as the climate changes it melts due the
warmth in wasanth ritu (autumn).
1c) Vyabhichari (weak factor)
This type of Hetu is weak and due to its weakness although it disturbs the
equilibrium of the doshas it is unable to lead to disease. An illustrating
example is that of our daily life where we resort to unhealthy practices but
doesn't always fall sick.
1d) Pradhanik (string factor)
Due to its strength these types of Hetu always lead to disease or death
after disturbing the equilibrium of the doshas.
An illustrating example is that of poison, snake bites, trauma etc.
2a) Asatmiya Indriyartha Sanjog
These types of factor are due tot he unhealthy or improper use of the
indriya i.e. gyan indriya (chakshu, srotra, ghran, rashna, sparsh ) and
karmindriya ( hasta, pad, wak, payu, upasth ) that lead to disease. These
Hetu are divided into the following categories:
- Atiyog (overuse)
This refers to the overuse of indriya. Example: reading for hours
together, watching T. V for long and working on computers for hours
together develop disease related to eyes due to the overstrain or
overuse of eyes.
- Hinyog (underuse)
This refers to the under use or less use of indriya that lead to
disease. Example: if we keep the eyes close for longer than the sleep
hours or rest hours eyes may develop some disease.
- Mithyayog (misuse)
This refers to the wrong use or misuse of indriya. Example: seeing
towards bright light straight or reading in very dim light both are
misuse of eyes that lead to diseases.
2b) Pragyaparadh
This term comprises of two words i.e. Pragnya meaning intellect and apradh
meaning crime thus giving the whole term the meaning of doing wrong things
inspite of knowing about their negative side effects or consequences that
will lead to disease. In ayurveda it is said that pragyapradh is the main
cause of janpadodhwans (epidemic diseases). It is the crime performed by the
intellect and is classified into three groups that are as follows:
- Dhi (intellectual)
It refers to the onset of any disease due to the action performed by
his intellect as he doesn't know what are the adverse effects of the
action, lack of intellect.
Example: A person not knowing the bad effect of alcohol resorts
to drinking does so because of lack of intellect.
- Dhriti (awareness)
This refers to the onset of any disease due to factors or actions
performed by the person after knowing the adverse effects of the action
i.e. inspite of the awareness when one does wrong things.
Example: when a person knows that alcohol is bad for health but
still is addicted to it and is not able to leave it due to liking it or
weak will power.
- Smruti (memory)
It refers to the onset of ailment due to the loss of memory.
Example: A person who is aware of the bad effects of alcohol
decides not to drink in future but drinks forgetting that he had
resolved not to drink he is termed as smrutivibhrast.
2c) Parinama (time)
Parinama refers to the prime factors that change the world and is
classified under the following three categories:
- Hinayog
Less cold in winter is considered as hinayog of winter season, which
effects our body and leads to disease.
- Mithyayog
If there is unexpected rain in winter is considered as mithyayog of it.
It also effects our body and leads to disease.
- Atiyog
Extreme cold in winter is considered as atiyog of it. It effects our
body, which leads to disease.
3a) Dosha Hetu
This refers to the Hetu that disturbs the equilibrium of any particular
dosha but doesn't lead to particular disease.
Example: intake of sugar causes disequilibrium in kapha dosha but
doesn't lead to any disease in particular.
3b) Vyadhihetu (diseased factor)
This refers to the cause of disease that is direct and can be identified
immediately as the cause.
Example: eating soil always leads to anemia.
3c) Ubhayahetu (combined factor)
It is the situation when both the disease and disturbance of thed oshas is
identified with the same factor or cause.
Example: Eating chilies or spicy food during travelling by any
vehicle or any other means of transport leads to disease called vatarakt (
gout). The dosha disturbed in this case is vata.
4a) Utpadakhetu (Predisposing Factor )
This refers to the situation where the factor is responsible for disturbing
the equilibrium of the dosha but may or my not be responsible for the
disease.
Example: Coldness of winter disturbs the equilibrium of kapha dosha
in the body but it does not lead to any disease.
4b) Vyanjakhetu (exciting factor)
This refers to the factors, which are not responsible for disturbing the
dosha but exciting them to lead to the disaaese. Example: Warmth of vasant
(autumn) does not disturb the equilibrium of kapha dosha directly but its
warmth melts the disturbed kapha dosha, which leads to disease.
5a) Bahyahetu (external factor)
This refers to the disease causing factors that are present outside the
body.
Example: Diet, conduct, time, microorganism, trauma, insect bite,
lightening, poisons, etc.
5b) Abhyantarhetu (interanl factors)
This refers to the factors present inside the body.
Example: Dosha, Dhatu and Mala of the body.