The fluctuations are of five types, painful or non-painful.

Patañjali begins to classify systematically. The vṛttis are divided into:

• Kliṣṭa — Painful, causing suffering, increasing the kleśas (afflictions)
• Akliṣṭa — Non-painful, neutral or beneficial

This distinction is practical: not all mental activities are obstacles. A thought can be correct (pramāṇa) and not cause suffering. The goal is not to eliminate all mental activity, but those that perpetuate confusion and pain.

The five types are described in the following sutra.