01 — Snakebite: suction
Do not cut the wound. Do not suck out the venom. These actions cause harm without removing meaningful amounts of venom.
The myth
After a snakebite, cut an X over the fang marks and use your mouth or a suction device to draw the venom out before it spreads.
What the AHA and Red Cross say
Suction removes only a trivial amount of venom and aggravates the local tissue injury. Cutting the wound risks serious infection and additional tissue damage. Commercial suction kits sold at outdoor stores are not recommended by any major medical organization. These actions waste time that should be spent getting to emergency care.
Venom from a North American pit viper spreads through the lymphatic system and binds to tissue very quickly. By the time a person could cut and suction a snakebite wound, the small fraction of venom near the surface is already being absorbed and the action causes additional injury at the bite site. Studies have shown that suction kits produce tissue damage at the suction site and do not improve outcomes. The AHA and Red Cross 2024 guidelines list suction among the interventions that are potentially harmful for North American snakebites.
What to do instead:
- Call 911 or emergency services immediately for any venomous or possibly venomous snakebite.
- Keep the person calm and as still as possible. Movement increases the rate at which venom spreads through the lymphatic system.
- Immobilize the bitten extremity and keep it at or below the level of the heart.
- Remove rings, watches, and constricting clothing near the bite before swelling begins.
- Note the time of the bite and monitor for symptoms. If possible, note the snake's appearance without approaching or capturing it.
- Do not apply ice, a tourniquet, or electric shock. Do not give alcohol. Get to emergency medical care.
Antivenom is the definitive treatment for significant envenomation. It must be administered by medical personnel. The faster the person reaches a facility that carries antivenom, the better the outcome.
02 — Hydrogen peroxide for wounds
Hydrogen peroxide kills the cells that close wounds. It delays healing and is no longer recommended for wound cleaning.
The myth
Hydrogen peroxide cleans wounds effectively and is a good antiseptic to keep in the first aid kit. The bubbling means it's working.
What the evidence says
The bubbling is real — it's oxygen released by the breakdown of hydrogen peroxide. But the same process that produces bubbles also destroys fibroblasts, the cells responsible for closing and healing the wound. NIH and wound care guidelines no longer recommend hydrogen peroxide for wound cleaning. Clean running water with mild soap is the correct approach.
Fibroblasts migrate to the wound site to begin the tissue repair process. Hydrogen peroxide, rubbing alcohol, and iodine all kill these cells indiscriminately. A wound cleaned with hydrogen peroxide may look cleaner in the short term, but it will take longer to close and has a higher risk of scarring compared to a wound simply irrigated with clean water. The NIH explicitly recommends against using hydrogen peroxide, iodine, or alcohol on open wounds.
The correct wound cleaning sequence is: rinse with clean running water for at least five minutes to remove dirt and debris; clean the surrounding skin (not inside the wound) gently with mild soap; apply antibiotic ointment to prevent infection; cover with a clean non-stick dressing. If debris cannot be removed by rinsing alone, seek medical care — do not probe the wound with tools or use chemical disinfectants in an attempt to substitute for professional cleaning.
Hydrogen peroxide has legitimate uses (diluted, for certain oral health applications under medical guidance), but wound cleaning is not one of them.
03 — Nosebleed: tilting the head back
Tilting back sends blood down the throat. The correct position is head slightly forward, pinching the soft part of the nose.
The myth
Tilt the head back during a nosebleed to slow the bleeding.
What the Red Cross says
Tilting the head back does not slow the bleeding — it redirects it into the back of the throat. Blood pooling in the throat can cause choking, nausea, and vomiting. It also makes it harder to apply effective pressure. The correct position is sitting upright with the head tilted slightly forward, pinching the soft part of the nose continuously for 10 to 15 minutes.
The head-back position is a reflex response — the person feels blood flowing forward and instinctively tilts back to keep from making a mess. But the volume of blood does not change; it simply goes into the throat instead of out of the nose. Swallowed blood irritates the stomach and causes nausea, and blood in the airway risks aspiration. Forward position lets blood drain out naturally, allows pressure to be applied correctly, and keeps the airway clear.
The mechanism of the correct technique: pinching the soft part of the nose (below the bony bridge) compresses the blood vessels responsible for most nosebleeds. Holding continuously for 10 to 15 minutes allows a clot to form. Releasing too early disrupts the forming clot and restarts the bleeding.
This myth has enough coverage on the nosebleed section of the bleeding control page — see that page for the full protocol, including when a nosebleed requires medical care.
Quick reference
- Snakebite: do not suction or cut; call 911, keep person still, immobilize limb, remove constrictions; do not apply ice, tourniquet, or alcohol
- Hydrogen peroxide: do not use on open wounds; it kills fibroblasts (the cells that close wounds) and delays healing; clean water is correct
- Nosebleed: tilt forward, not back; tilting back sends blood into the throat causing nausea and aspiration risk; pinch soft part of nose for 10 to 15 minutes without releasing
- The bubbling from hydrogen peroxide is not "killing bacteria" — it is destroying healing tissue
- Suction kits sold at outdoor stores are not recommended by the Red Cross, AHA, or CDC for snakebite
Primary sources
- Red Cross — 2024 First Aid Guidelines Summary: Snake bites: activate emergency services for any venomous or possibly venomous snakebite; rest and immobilize the bitten extremity; ice, suction, electric shock, tourniquets, and pressure immobilization bandaging are potentially harmful for North American snakes.
- AHA — Part 17: First Aid (Circulation): Do not apply suction as first aid for snakebites (Class III, LOE C); suction removes only a small amount of venom and may aggravate the injury.
- WebMD / NIH — Wound Care Dos and Don'ts: Using hydrogen peroxide or rubbing alcohol to clean an injury can damage tissue and delay healing; clean running water and mild soap are the correct wound irrigation method.
- Red Cross — Nosebleed: Sit with head slightly forward (not back); tilting back causes blood to pool in the throat, which can lead to choking or vomiting; pinch nostrils continuously for 10 to 15 minutes.