Duhkha a fundamental concept in Indian philosophy and religion. Etymologically the absence of happiness is duhkha or suffering. The term 'duhkha' is used in diverse senses, viz, affliction of the body, affliction of mind, pain, sorrow, trouble, grief, misery, woe, tribulation, anguish, etc.
One of the fundamental teachings of the Upanishad is that suffering is an unavoidable fact of human life. Xevtaxatara Upanishad inequivocally comments that this world is full of duhkha or suffering. The concept of suffering occupies a unique place in Jainism. A tragic picture of the human life is depicted in one of the main scriptures of the Jaina religion, the Uttaradhayana Sutra: There is a vision of fear, pain and suffering everywhere and I have felt sorrow and agony with no rescue for even a moment from this perpetual sorrow.
The painful picture of sorrows and sufferings is particularly depicted in the Buddhist concept of religion. The initiation of the Buddhist religion and philosophy was manifested with sorrows and sufferings of human being. The Buddha holds: Birth is painful, decay is painful, disease is painful, death is painful, union with the unpleasant is painful, painful is the separation from the pleasant, and any craving that is unsatisfied, that too is painful. Gautama Buddha's basic teachings are his four-fold Noble-Truths. These are: a. There is suffering, b. There is cause of this suffering, c. There is cessation of this suffering and d. There are paths which will lead to the cessation of suffering. According to Gautama Buddha, whatever is changeable is full of suffering; everything in this universe is changeable, so everything is full of suffering. We fall victim of sorrow since we fail to understand the fact. According to Buddha, the more we desire the more suffering we face. There is no end of desire, so there is no end of suffering. It is only the freedom from ignorance that can make our eternal salvation (Nirvana) possible. [Azizun Nahar Islam]