Why is my fish bloated?

What to check first

• Test ammonia, nitrite, nitrate and temperature
• Look for pineconing, ulcers or asymmetry
• Review recent feeding and access to food
• Consider pregnancy or egg development in the species

Write down the test results, recent maintenance, new livestock, feeding changes and equipment faults. A short timeline prevents repeated guesses and makes patterns easier to see.

A practical action plan

1. 1. Photograph the fish from both sidesRecord what changes and retest before making another major adjustment.
2. 2. Move it to a suitable hospital tank when neededRecord what changes and retest before making another major adjustment.
3. 3. Stop random medication and collect observationsRecord what changes and retest before making another major adjustment.
4. 4. Contact an aquatic veterinarian for severe or persistent swellingRecord what changes and retest before making another major adjustment.

What to avoid

Do not squeeze the fish, puncture swelling or use peas and salt as universal cures.

When it is urgent

Pineconing, inability to swim, rapid breathing, bleeding or sudden worsening warrants urgent veterinary advice.

How to prevent it next time

Use stable routines: quarantine additions, test before and after major changes, maintain backup aeration, keep equipment accessible, and record enough detail to compare today with the aquarium’s normal baseline. Prevention is usually cheaper and safer than emergency correction.