How to Treat Fish Swim Bladder Disease

What Is Swim Bladder Disease?

Swim bladder disease is a condition where a fish loses its ability to control its buoyancy. The swim bladder is an internal gas-filled organ that allows fish to maintain their position in the water column. When it's not functioning properly, fish may float uncontrollably at the surface, sink to the bottom, swim sideways, or struggle to maintain an upright position.

Swim bladder disease is a symptom rather than a single disease — it can have several different causes, each requiring a different approach.

Signs of Swim Bladder Disease

Floating at the surface unable to dive down
Sinking to the bottom unable to rise
Swimming sideways or upside down
Curved or S-shaped spine
Distended or swollen belly
Difficulty eating due to abnormal positioning

Common Causes of Swim Bladder Disease

1. Overfeeding and Constipation (Most Common)

The most frequent cause, especially in goldfish and bettas. An overfull digestive tract or constipation puts pressure on the swim bladder, disrupting its function. This is the most treatable form.

2. Gulping Air

Fish that feed at the surface can gulp air along with food, causing temporary swim bladder issues. More common with dry flakes and pellets.

3. Bacterial Infection

Internal bacterial infections can cause inflammation around the swim bladder. Usually accompanied by other symptoms like lethargy, loss of appetite, and bloating.

4. Physical Injury or Birth Defect

Trauma from rough handling or a congenital defect. These cases may be permanent.

How to Treat Swim Bladder Disease at Home

For Constipation-Related Swim Bladder Issues

Fast the fish for 2–3 days — no food at all. This is often enough to resolve mild cases.
Feed blanched, shelled peas after the fast — peas act as a natural laxative for fish. Remove the outer skin and cut into small pieces appropriate for your fish's size.
Raise the water temperature slightly (1–2°F) to stimulate digestion.
Soak dry food before feeding going forward — pre-soaking pellets and flakes for 30 seconds reduces air ingestion.

For Infection-Related Swim Bladder Issues

If fasting and peas don't improve the condition within 3–5 days, bacterial infection may be involved. Treat with a broad-spectrum antibacterial product. The MICROBE-LIFT Artemiss supports immune function and helps fish recover from bacterial infections affecting internal organs.

Quarantine the affected fish in a separate tank or use the Fluval Multi-Chamber Breeding Box to isolate it within the main tank during treatment.

Supportive Care

Lower the water level to reduce the effort required for the fish to reach the surface to breathe
Ensure excellent water quality — test with the Varify 17-in-1 Water Test Kit and do a 25% water change if parameters are off
Provide easy access to food — a fish that can't swim normally may struggle to reach floating food

When Swim Bladder Disease Is Permanent

Some fish — particularly fancy goldfish with compressed body shapes — develop chronic swim bladder issues that can't be fully resolved. These fish can still live comfortably with supportive care: a shallow tank, easy food access, and excellent water quality.

Preventing Swim Bladder Disease

Don't overfeed — feed only what fish consume in 2–3 minutes
Soak dry food before feeding
Fast fish one day per week
Feed blanched peas weekly to goldfish and bettas as a preventive measure
Maintain excellent water quality

Final Thoughts

Most cases of swim bladder disease caused by overfeeding or constipation resolve with a 2–3 day fast followed by peas. Act quickly, address the root cause, and most fish recover well. For persistent cases, consult an aquatic veterinarian.

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