Claim Check: "Nose Breathing Fixes Sleep, Anxiety and Performance"

The claim

Social media often says that breathing through your nose fixes sleep, calms anxiety and improves performance, and that taping your mouth shut at night will get you there.

Our verdict: some real findings, but "fixes everything" is not supported

Nose breathing is described as the preferred pathway for quiet breathing [1], and in some sleep studies, blocking the nose made breathing during sleep worse. [2] The jump from there to "fixes" sleep, anxiety and performance is not backed by the studies we read. Evidence label: mixed overall; promising but limited for sleep airway findings; insufficient evidence for anxiety and performance; evidence of potential harm for mouth taping when the nose is blocked.

What the studies found

1. Nose breathing helps sleep

   Small, controlled experiment in healthy people

   In a randomized, single-blind crossover study of 12 healthy adults with normal nasal resistance, airway resistance during sleep was much higher when breathing through the mouth than the nose. [3] Breathing episodes that block the airway were far more frequent with oral breathing in that experiment. [3]

2. A blocked nose worsens sleep apnea signs

   Promising but limited

   A meta-analysis found that nasal obstruction was associated with worse sleep apnea indicators. [2]

3. Mouth taping helps

   Insufficient; possible harm

   Only two mouth-taping studies were reviewed narratively in that meta-analysis. [2] In a systematic review of 10 studies, two showed improvement in sleep apnea markers, while other studies showed no difference and discussed potential risks, including asphyxiation when the nose is blocked. [4] A scoping review found the literature markedly heterogeneous with little consensus on benefit. [5]

4. Nose breathing reduces anxiety

   Insufficient; one self-reported study

   A study in adolescents aged 15 to 18 found that all three active interventions reduced self-reported anxiety compared with controls, and those three were posture alone, nasal breathing alone, or both together. [6]

5. Nose breathing improves performance

   Small experiment; no output gain

   In 49 healthy adults doing two all-out Wingate anaerobic tests, perceived exertion was higher with oral breathing, but breathing mode did not change power output. [7]

6. Mouth breathing harms posture and jaw

   Very low certainty

   A review found very low certainty evidence of links with posture, jaw joint function and chewing muscle activity. [1]

What this means

• Sleep. If you snore, wake unrefreshed or may have sleep apnea, a blocked nose is worth raising with a clinician. A meta-analysis links nasal obstruction to worse sleep apnea indicators. [2] See our sleep apnea guide.
• Anxiety. The nasal-breathing anxiety finding comes from a single adolescent study using questionnaires after a stress test. [6] For gentle breathing for stress, the NHS describes breathing in through the nose and out through the mouth, as deep as is comfortable, without forcing. [8]
• Performance. The performance experiment found no difference in power output. [7]
• Mouth habits. Up to 30% of the population are described as habitual mouth breathers. [1] That alone does not tell you whether anything is wrong.

Where to go next

Read what research shows in nasal and mouth breathing and about mouth tape, nasal strips and airway devices.