Exhaustion

Exhaustion has six levels. Subtract twice your Exhaustion level from D20 Tests (ability checks, attack rolls, and saving throws). Reduce your Speed by 5 feet per level. You die at level 6. Finishing a Long Rest removes one level, provided you also eat and drink as the rules require. Apply these penalties alongside other character effects.

Source: supplied Player’s Handbook (2024), chapter 1 and Rules Glossary. This is a paraphrased quick reference; specific features can override the general rules.