Guide
Swim bladder disease in fish
Floating, sinking, or listing — common causes and what to try first.
- Not one disease: Swim bladder “disease” is a symptom — overfeeding, constipation, infection, or injury can be involved.
- First steps: Test water (0 ammonia, 0 nitrite); fast the fish 1–2 days; offer a pea (skin removed) for some species.
- Serious signs: Bloating with scales sticking out, or rapid decline — may need veterinary diagnosis.
What you are seeing
Fish may float at the surface, sink to the bottom, or swim at an angle. The swim bladder is an internal gas organ; when it does not function properly, buoyancy is affected.
Common causes
Overfeeding and constipation (especially common in goldfish and bettas), poor water quality, sudden temperature drops, physical injury, or internal infection. Parasites and organ damage are less common but possible.
What to try first
Improve water quality with a test and partial change if needed. Fast the fish briefly. For goldfish, a peeled pea can help constipation. Avoid chasing miracle cures until basics are ruled out.
When to escalate
If the fish stops eating, develops dropsy-like swelling, or deteriorates quickly, consult a fish vet or experienced aquarist. See common fish illnesses.
Track water tests and symptoms over time in App-aquatic.
Get the free appDoes pea cure swim bladder?
It can help constipation in some fish (e.g. goldfish) but is not a universal cure. Address water quality first.
Can swim bladder fix itself?
Sometimes, if the cause was mild (e.g. overfeeding). Persistent symptoms need more investigation.
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