Nīvarana: 'hindrances', are 5 qualities which are obstacles to the mind and blind our mental vision. In the presence of them we cannot reach neighbourhood-concentration upacāra-samādhi and full concentration appanā-samādhi, and are unable to discern clearly the truth. They are:
lethargy and Laziness thīna-middha,
restlessness and regrets uddhacca-kukkucca and
skeptical doubt vicikicchā.
In the beautiful similes in A. V, 193, sense-desire is compared with water mixed with many colours, ill-will with boiling water, lethargy and Laziness with water covered by moss, restlessness and regrets with agitated water whipped by the wind, skeptical doubt with turbid and muddy water. Just as in such water one cannot perceive one's own reflection, so in the presence of these 5 mental hindrances, one cannot clearly discern one's own benefit, nor that of others, nor that of both.
Regarding the temporary suspension of the 5 hindrances on entering the first absorption, the stereotype sutta text e g. A. IX, 40 runs as follows:
He has cast away sense-desire; he dwells with a heart free from sense-desire; from desire he cleanses his heart.
He has cast away ill-will; he dwells with a heart free from ill-will, cherishing love and Pity toward all living beings, he cleanses his heart from ill-will.
He has cast away lethargy and Laziness; he dwells free from lethargy and Laziness; loving the light, with watchful mind, with clear consciousness, he cleanses his mind from lethargy and Laziness.
He has cast away restlessness and regrets; dwelling with mind undisturbed, with heart full of peace, he cleanses his mind from restlessness and regrets.
He has cast away skeptical doubt; dwelling free from doubt, full of confidence in the good, he cleanses his heart from doubt.
He has put aside these 5 hindrances, and come to know these paralysing defilements of the mind. And far from sensual contacts, far from disadvantageous things, he enters into the first absorption, etc
The overcoming of these 5 hindrances by the absorptions is, as already pointed out, a merely temporary suspension, called 'overcoming through repression' vikkhambhana-pahāna. They disappear forever on entering the 4 supra-mundane paths see: ariya-puggala i.e. skeptical doubt on reaching Sotāpanship; sense-desire, ill-will and mental worry on reaching Anāgāmiship; lethargy, Laziness and restlessness on reaching Arahantship.