Buddhism is a system of philosophy with a code of Morality, Physical and Mental. 
The Goal in view is "Cessation of Suffering and Death."

1. Dukkha Sacca = Noble Truth of Suffering,
2. Samudaya Sacca = Noble Truth of Origin of Suffering,
3. Nirodha Sacca = Noble Truth of the Cessation of Suffering,
4. Magga Sacca = Noble Truth of the Path leading to the Cessation of Suffering.

To come to a complete understanding of the fundamental concepts in the philosophy of the Buddha, 
emphasis is laid on the need for the realization of the Truth of Suffering.
 

What is the truth of suffering ?

The Meaning du = difficult , kha = to endure

There are 3 Types of Dukkha
1 Dukkha-dukkhata : 
    Suffering of the mind and body in ordinary sense includes pain, etc

2 Sankhara-dukkhata: 
    Suffering of the Aggregates ; state of dis-ease and instability, 
    the rising and falling away of the momentary phase of existence.

3 Viparinama-dukkhata : 
    Dukkha cause by change or transience. 
    All things are anicca ( impermanent ) therefore there is no eternal soul or unchanging physical and
    mental force or energies ( anatta ).

Birth (jati), old age / decay (jara), sickness (vyadhi), death (marana), association with the unpleasant, 
separation from the loved, not getting what one desires and obtain what one does not desire are another dimension of suffering.

It is Moha ( Delusion ) that keep us away from this Truth of Suffering. 
The Buddha also pointed out that the body of all beings is composed of Kalapas (atomic units), each dying out simultaneously as it becomes.

Each Kalapa is a mass formed of the following nature elements :

1 Pathavi = Extension ( Lit. earth )
2 Apo = Cohesion ( Lit. water )
3 Tejo = Radiation ( Lit. heat and cold )
4 Vayo = Motion ( Lit. air )
5 Vanna = Colour
6 Gandha = Smell
7 Rasa = Taste
8 Oja = Nutritive essence

The first four is called Mahabhuta ( essential material qualities ) which are predominant in a Kalapa. The other four are the subsidiaries which are dependent upon and born out of the former. It is only when the eight nature-elements ( the characteristic of behavior ) are together that the entity of a kalapa is formed.

These kalapas are in a state of continuous change or flux. They are nothing but a stream of energies, just like the electricity that form the light in the bulb. Therefore the body as we call it, is not an entity as it seems to be, but a continuum of matter with life-force co-existence.

In conclusion, grasping of the 5 Khandas ( aggregates ) is suffering. The 5 aggregates arises in every thought ( mental activities ) and they have the characteristics of rising and falling. There are no substance or value in them and they are just the vibration of the energies. The more one is attached to it which we always consider it as Self, the greater is the suffering.

The 5 aggregates are rupa (form), vedana (feeling), sanna (perception), sankhara (mental formation) and vinnana (consciousness).

The process of the mental activities describe are:
1. contact of a form/object through any of the sense doors,
2. feeling arise from the above contacts,
3. perception ,
4. the mental volition
5. attention

The Origin of it is Tanha or craving. Once the seed of desire is sown, it grows into greed and multiplies into craving or lust, either for power or for material gains. Thus one becomes a slave to these cravings and automatically driven into strenuous labours of mind and body to keep pace with them till the end comes.

The final result must surely be the accumulation of the evil mental force generated by one own actions, words and thoughts which are motivated by Lobha (desire) and Dosa (anger) inherent in oneself.

It is the ceaseless striving for pleasures and sensation in obtaining self-satisfaction that arouse more desires. The attachment to these sense-objects and the not knowing or ignorance ( avijja ) that they are impermanent ( anicca ) lies the cause of dukkha, which manifested as craving.

Three types of Craving

1. Sensual Craving (kamatanha)
    Contact of the sense organs through sights, sound, ordure, tastes. tactile sensations and
    mental impression contribute to sense perception.

2. Craving for Existence (bhava tanha)
    Desire to be reborn in the sensual spheres (kama-loka), fine material spheres (rupa-loka) or 
    formless spheres (arupa-loka)

3. Craving for Self-Annihilation (vibhava tanha)
    Erroneous view that the aggregates of phenomenal personality constitute a soul 
    which is annihilated (complete destruction) at death.

Underlying the second Noble Truth is one of the cardinal principles of the Buddha's teaching, that everything is the result of the cause, every cause has an effect. There are many causes; ignorance and craving are the two links in the chain of causes that results in birth, decay and death. This is known as the Law of Kamma and Rebirth.

The Cessation of dukkha is equal to the cessation of Craving. The state in which there is complete freedom from suffering and bondage into unspeakable joy, happiness and peace is called Nibbana ( the unconditioned ).

It can only be achieved by a total eradication of all forms of craving.