StillBox

Safety

Last updated: 2026-08-20

StillBox is a wellness tool, not a medical device. It is not intended to diagnose, treat, cure, or prevent any disease or condition, and it does not give medical advice. Talk to a doctor before starting a breathing practice and before making any decision about your health.

Rules

Never practice in or near water. Holding your breath after fast or deep breathing can cause a blackout with no warning signs. In water this is fatal. Practice on dry land only.

Never practice while driving, cycling, or operating machinery.

Sit or lie down. Some people feel lightheaded, dizzy, or tingly during breath holds. Sitting means a faint does not become a head injury.

Stop if it feels wrong. If you feel dizzy, faint, short of breath, chest pressure, or rising panic, end the session and breathe normally.

Check with a doctor first if

• You are pregnant
• You have a heart condition or high or low blood pressure
• You have asthma, COPD, or another respiratory condition
• You have a seizure disorder
• You have glaucoma or a history of retinal detachment
• You have a history of fainting
• You have a panic, anxiety, or trauma-related condition

Paced breathing and breath holds make some people feel worse rather than calmer. That is a known response, not a failure on your part. Stop and talk to a clinician.

Children

StillBox is not designed for young children. Breath-hold exercises should not be practiced by children without adult supervision.

This is not a crisis service

StillBox cannot help in an emergency. In the United States, call or text 988 to reach the Suicide and Crisis Lifeline. Outside the United States, call your local emergency number.

Sources

• Royal Life Saving Society UK, guidance on hyperventilation and breath-holding
• American Red Cross, YMCA of the USA, and USA Swimming joint statement on hypoxic blackout
• Shallow water blackout, StatPearls (NIH)