Swim bladder disease: Is your fish swimming upside down?

Swim bladder disease is one of the most common problems affecting goldfish. If you’ve seen your fish swimming upside down or on its side, then you’ve seen a swim bladder problem.

Although often called a “disease”, it is actually a symptom that can have a number of different causes. There is not one specific “disease” that is the cause of all swim bladder problems in goldfish.

Proper goldfish care can prevent most swim bladder problems.

As it is not actually a disease, swim bladder problems are not contagious. If one fish has a problem, your other fish won’t “catch it”. However, they may still be at risk of developing similar problems.

Fortunately, swim bladder problems can usually be cured fairly easily, as long as you spot them early enough.

If you see your fish swimming upside down or on its side, act quickly!

There are several good swim bladder treatments available. But, before you try to cure your fish, read on to find out more about treating swim bladder problems.

What is swim bladder disease?

Swim bladder disease is when a fish loses its ability to regulate the air going in and out of its swim bladder. This causes the fish to swim strangely, on its side, or even upside down.

The job of the swim bladder is to help the goldfish stay stable in the water and control the way in which it floats.

If the goldfish wants to swim upwards, towards the top of the tank, then it will take air into its swim bladder. This makes the goldfish more buoyant (like an inflatable in a swimming pool) and it rises towards the surface.

If the goldfish then wants to swim downwards, towards the bottom of the tank, it will release air from the swim bladder. You may see this air coming out of the fish’s mouth in the form of bubbles as it swims to a lower point in the tank.

Why Is My Fish Swimming Upside Down?

If your fish is swimming upside down, it has a problem with its swim bladder.

Your fish has stopped being able to control its swim bladder and has got stuck with too much air inside it.

The reason for this could be constipation, a poor diet, eating habits, or an infection.

What Causes Swim Bladder Problems?

Causes of swim bladder problems include:

  • Constipation, which results in excess food pressing against the swim bladder. This is a common problem in goldfish, which you can read about here.
  • Swallowing air at the surface of the tank when eating
  • Eating the wrong kinds of food, which then ferment in the gut
  • Sudden changes in temperature
  • Bacterial infection
  • Parasitic infection

Fancy goldfish often suffer from deformed swim bladders, as they have been bred to have such unusual body shapes.

Symptoms of Swim Bladder Disorders

Identifying swim bladder disorders can be challenging, but certain symptoms such as abnormal swimming patterns, difficulty maintaining balance, and floating or sinking issues can indicate a problem. Observant fish owners can play a crucial role in early detection.

What Do Swim Bladder Disorders Look Like?

Swim bladder disorders in fish manifest in various ways, and recognizing the signs is crucial for prompt intervention. Understanding what to look for can help fish owners identify potential issues and take proactive steps to address them. Let’s delve into the visual cues that indicate a fish may be experiencing swim bladder disorders.

Orange banner with the words "5 easy steps to treat"

Treating the problem in 5 easy steps

Swim bladder problems can be very serious. But there is hope! It is also one of the most straightforward issues to treat.

Follow these 5 simple steps:

  1. Test the water quality and temperature using a test kit. Is the tank properly cycled? Do you do regular water changes? Is there ammonia or nitrite in the water? Is the temperature stable? If not, you need to urgently take action to improve and stabilize your water parameters.
  2. Do not feed the fish for at least 48 hours. Don’t worry – goldfish really don’t need to eat much!
  3. After 48 hours, start to hand feed the fish very small amounts of peas with the shells removed in order to clear up the blockages.
  4. Add some aquarium salt (one teaspoon per gallon) to de-stress the fish. You can buy aquarium salt online or at pet stores.
  5. Try a specific swim bladder treatment.
  6. Try a treatment for bacterial infection such as API Melafix.

You should soon see your goldfish start to swim in a more stable, upright position.

Balancing Your Pond Fish’s Diet

With the arrival of autumn, it becomes essential to modify your fish’s diet to align with the shifting water temperatures. The decrease in temperatures during the fall season can noticeably decelerate their digestive processes, which can be the leading cause of enlarged intestines.

Stopping it from happening again

After your fish has recovered from swim bladder disease, you should consider making changes to their diet.

Here are 5 top tips to prevent swim bladder problems.

  • Read our article on feeding goldfish and feeding a varied diet to your fish.
  • Feed sinking pellets instead of flakes. You can find out more about pellets in our guide to feeding pellets to your goldfish.
  • Feed your goldfish peas with the shells removed, boiled vegetables, bloodworms, and brine shrimp.
  • Soak food in tank water for a few seconds before adding it to the tank. This will make sure it sinks and stop your goldfish from gulping air at the surface.
  • Feed less regularly. Goldfish really don’t need to eat much at all. There is much more risk of over-feeding your goldfish than there is of under-feeding them.


In conclusion, swim bladder disease poses challenges in the realm of fishkeeping, but with awareness, preventive measures, and timely intervention, its impact can be mitigated. Stay attuned to your fish’s behavior, provide optimal care, and foster a community of shared knowledge to ensure a thriving aquatic environment.


  1. How can I prevent swim bladder disease in my fish?
    • Maintaining water quality, offering a balanced diet, and monitoring behavioral changes are key preventive measures.
  2. What are the common signs of swim bladder disease?
    • Unusual swimming patterns, buoyancy issues, and erratic movements are indicative of swim bladder disease.
  3. Can swim bladder disease be cured at home?
    • Mild cases may respond to conservative treatments, but severe cases often require professional veterinary intervention.
  4. Are certain fish species more prone to swim bladder disease?
    • Yes, some species are more susceptible, highlighting the importance of species-specific care.
  5. How quickly should I seek treatment if I suspect swim bladder disease?
    • Swift action is crucial; delaying treatment can lead to irreversible consequences.

53 thoughts on “Swim bladder disease: Is your fish swimming upside down?”

  1. My black moor has been bullied and harassed by my fancy orando goldfish which has resulted in me removing the Moor. He became exhausted. He also started swimming on his side
    Since putting him in a separate tank ..I think it seems he has swim bladder. Ive witnessed him swimming along the bottom on his side, struggling to stay straight and volant and for the past two days hes just at the bottom of the tank. When I enter the room he wiggles a but but then looks as if he’s just going back to sleep.
    Hes fins look fine no signs of rot.
    I changed the water yesterday and introduced more if the original fish tank water in to his hospital tank.
    But am so worried. I think he must be suffering.
    If its swimbladder I will fast him for 3 days and introduce some shelled peas.
    Do I also need salts…or a commercial medicine.
    Its so stressful to see them struggle.
    Ive had him about 9 months no problems

    • Did your fish recover? Because i have a black more and he is doing that exact same thing like exactly the same. If you’re fish did recover what did you do to help it? Thanks so much

      • Did any of your black moor recover because we have two but one of them is doing the exact same thing and we separated him from the others because they would push him around but I really feel so sad for him and want him to be back well any options or anything

        • does anyone here had their fish recovered? mine i just laying on its side the whole time, and swims in circles while sinking. i did fasting, increase the temperature and the water is okay.

          • Swim bladder can have many different causes and depending on the cause can depend on whether or not the fish recovers.
            Swimbladder by itself cannot kill a fish, but what can happen is the fish is unable to eat, is killed by something else, or becomes stressed and has its immune system compromised.

            the best cure for swim bladder in most cases is to leave the fish alone, stress is the biggest killer for fish, but you can provide them with supportive care to help them get through it.

            frozen peas and green beans are really good foods for fish with swim bladder or bloat.

            if your fish is being picked on, then separate it from the rest to allow it to recover on its own.

            If the condition is prolonged over a long period and your fish shows other signs of ill health, then try an antibiotic.

            Raising temperature can help, but it does cause stress and reduces the oxygen level, we recommend increasing aeration with an airstone if you do this.

            As mentioned swim bladder cant kill a fish on its own, but stress can, reducing it as much as possible is the best way to help your fish recover.
            hope this helps.

        • Hi,
          we would recommend stopping any currents you have in the water, while still allowing filtration to take place, perhaps use sponge filters if you arent already, as they produce no current.
          we would then also recommend feeding sinking foods and veg, like frozen peas, and canned green beans.

          You could also try reducing the water level to make life easier for your fish, and keeping an eye on it for any other signs of ill health.

      • Hi Sarah, thanks for your comment,
        we are glad to hear that you managed to treat your danio!

        Swim bladder has a wide range of causes and is very difficult to pinpoint as it is very situational.

        anti parasite meds have compounds in them which also treat bacterial infections, this was possibly what was causing the swim bladder in your fish.

        unfortunately this is not applicable to all cases as swim bladder isn’t always caused by bacteria or parasites, sometimes a goldfish can even physically damage its swim bladder through abrasion.

        We normally only recommend using treatments when they are absolutely necessary, and when a cause or illness can be properly identified first

        • Hi Lewis, my fish I think has swim bladder I’m really worried she’s in pain she’s a powder blue gourami fish, and she was very energetic, and barley swims or eats. Since I am a beginner I don’t have some of the things here. So, do you think quarantining my fish would be good too?

          • Hi Nichole, thanks for your comment.
            How long has she been like this? if it has been over a week then we would recommend quarantining as it can give them extra support.

            If she hasnt been like this for very long, then we would say leave her and observe closely for a while.

            Remember, swim bladder on its own cannot kill your fish, what can is starvation, or being picked on by other fish.

            Try feeding her cut up frozen peas or green beans, they are a really good food for fish with congestion issues.
            It can be a little tricky since gourami can be picky eaters at times, but if she doesnt eat, keep trying her on different foods, maybe give her frozen bloodworm or brine shrimp, just so she has something to eat at the very least.

            Keep the water quality clean and keep feeding, and most of the time they will pull through on their own, if you feel the need to give extra support then quarantining is a good idea.
            You can use a floating breeder box to do so in the same tank, which is your cheaper and probably less stressful solution, or set up another smaller tank, just use the same water from her tank if you do this to minimise stress.

            If she has swimming troubles for any more than 14 days, try an antibiotic treatment.

            Hope this helps, and good luck with your gourami 🙂

    • I have a angel fish was doing fine night before all of a sudden now I have 2 angel fish that are bent and basically sitting on bottom trying to swim but just pushing it self around the bottom

  2. One of my goldfish which are Shubenko species (a Japanese variety, I think), developed swim bladder problems. I followed some advice and did partial water changes each day for a couple of days to make sure the water was cool enough ( it is humid where I live) and to remove excess nitrogen. I then added the prescribed amount of tropical conditioning salts to my tank (to cover the whole volume of water in it) and then with each partial water change since, I’ve added the right dose to the new amount of water. At that time I also fasted the fish for 48 hrs then started feeding them 1/2 a pea a day each. Within a few days the affected fish’s buoyancy improved although 3 to 4 weeks later it is still experiencing some problems, it’s swimming has improved a lot and they are still on the pea diet. I’m going to introduce sinking pellets to them or maybe live food like brine shrimp so they don’t gulp in air at the surface while feeding. Hopefully the fish will continue to improve but I will keep checking on his behaviour daily. Hope your fish get better. Gabrielle

    • Thank you for your comment Gabrielle,
      This is some great information for anyone dealing with buoyancy issues!
      we are glad to hear that you were able to provide excellent supportive care for your shubunkins!
      and yes you are correct, they are a breed of japanese origin

  3. I have a pond of shubunkins and 2 of them have started acting funny; one of them hardly swims and mostly just lays near the bottom of the pond with his face downward and his body slanted upward but just a few days ago he was swimming upside down and laying upside down, the second fish swims perfectly fine but rests near the bottom a decent amount just like the other fish (head down and body slanted upward) are these also signs of swim bladder?? I’m not quite sure…

  4. My little comet just started swimming funny last night not really swimming much and being on the bottom of the tank, today and tonight it’s laying on its side on the bottom I put it in a bowl instead of the big tank with the my 4 other goldfish we’ve had the comet about a year and a half what can should I do?

  5. hello,
    i have a pair of fancy goldfish in a 23 gallon tank and at some point last night one got his fin stuck in the filter vent, it’s not damaged when we got him out of it but he is swimming on his side and upside down. I turned the light off, added a bit of aquarium salt to help him not stress out, but it’s been a few hours and he’s still not upright totally. Is there anything else I can do or do I just need to wait a while longer?
    I will add that he is quite old, a little more than five years, and he’s never had issues before other than little scratches and stuff like that.

    • Hi Victor, thanks for your comment,

      Sometimes the best thing to do with swim bladder is to wait it out, while aquarium salt can help, it is not always necessary and can cause stress to the goldfish as it makes the water conditions change.

      Perhaps reduce the power of your filter so that the fish are not fighting against a current, this will allow them to heal better.

      Also 5 years is actually quite young for a goldfish, as they can live around 30+ years in good conditions.

      We hope you were able to cure your goldfish

    • Hi Anita,
      we recommend you boil the peas so they become soft, then cut them in halves and remove the shells, allow them to cool and then feed them to your goldfish.
      hope this helps.

  6. i have had my goldfish for nearly five years and it has been swimming on its side for about twenty or three weeks i have tried everything from cleaning my tank to changing its eating habits, i have got a new filter , i have tried the pea thing and nothing seems to be working, i don’t know what else to do, can you please advise me what i can do to fix this ? thank you

    • Hi martin, thanks for your comment,
      As mentioned above, swim bladder can be a result of many different causes, sometimes fish can permanently damage their swim bladder and may never fully recover.
      the best thing to do in these cases is to provide supportive care, but not stress out the goldfish, essentially as long as the water is clean and they are eating food, there is nothing else you can really do, in some instances swim bladder can become a permanent disability for fish.

      However, in most cases they will recover on their own, this is done in their own time and you cannot rush the process, some fish can have swim bladder for over a year and then suddenly recover like nothing happened.

      we hope you were able to cure your goldfish by now

  7. My goldfish is swimming straight up like gulping for air tale down all the time. I cleaned the tank yesterday and since then is swimming like this. Every now and then he drops down to the bottom then comes back to the top to look for air. Blows a bubble and stays there a few minutes.what could be the problem. I did put in salt. I have a 30liter tank, with 2 tables spoons salt and flakes for food.

    • Hi Danie, thanks for commenting,
      It sounds like your goldfish is suffocating, you need to add a form of aeration such as an air stone to allow oxygen to dissolve into the water, so your goldfish can breathe properly.
      I’m not sure on the salt situation, but it is not advised to add salt unless curing an illness as goldfish are freshwater fish, there should be no salt in the water.
      I would also consider upgrading the tank size as 30 litres is very small for goldfish (which can grow over 10″ long).
      hope this helps.

  8. So I’ve had a few Glow Tetras in a 15 gal tank for 5 months now. The orange tetra (the oldest by quite a bit) just started swimming to the top and swimming around on its side. I’m due to service the water and change the filter in the morning, but this is the first time this fish has done this???

    • Hi Landon, thank you for your comment,
      Have you tested your water to see if there is something wrong?
      While a water change can help it may not always be the best course of action, if you dont know the water chemistry, sometimes a water change can actually do more harm than good. If you havent already, I would recommend testing your water.
      If it is all clear, then look for other disease symptoms such as a “rusty or frosty” appearance on the skin and scales, glowlights often suffer from tetra disease, or fish tuberculosis, it is very common in store bought tetras.
      Sadly it is incurable, but you should separate the diseased tetra.
      It could also be a simple swim bladder issue, that could be caused by stress, damage or illness, it is hard to say, I would observe the others too, see if they have any symptoms as well.
      good luck with your glowlight tetras
      hope this helps.

  9. Hi
    My goldfish is suffering from swim bladder and I’m struggling to get them to eat the peas. Does anyone have any suggestions as to how I can get them to eat some? She isn’t eating and in scared to give her the normal flakes 🙁
    Thanks so much!

    • Hi Kim,
      Thanks for your comment, there are a number of ways you can feed peas to goldfish, the best way is to boil the peas until they become soft and then break them up.
      If they do not like frozen peas, then try green beans from a can, these are happily eaten by most fish and are already soft and easy to break up.

      If you fish doesnt eat peas at all, then do not worry, if your fish starts to lose weight or you are worried about them not eating you can feed them flakes, just push them down so they sink.
      The reason we recommend peas is that they are a laxative and help to push out any trapped air that could be causing swim bladder.

      Clean water, lack of stress and food should cure swim bladder in a lot of cases, peas arent really a magic food that cures them, they just help.

      hope this information is useful, and good luck with your goldfish 🙂

  10. I have four glo fish, and the large one, Kiwi, developed swim bladder. I checked the PH and did water changes correctly, then let them rest and stopped feeding Kiwi. He has slowly recovered and is swimming much better, thank you for all the tips!

  11. Hi – we have a beta fish that started floating and swimming on his side a few days ago. We moved him to a smaller bowl, fed him a pea, he went to the bathroom and improved. We cleaned his regular tank well, changed the filter and put him back. Now in less than 36 hours he’s back to floating. We’ve given him one pellet but other than that have not fed him in 4 days. Scratching our heads here. The pea definitely seemed to help him as he was finally able to hangout at the bottom of the hospital tank. Now, since being back in his regular tank, he’s having trouble again. What else could it be???

    • Hi Coralina,

      Perhaps there is something in the main tank causing it, have a test of the water, check the filtration, perhaps too much flow?
      Perhaps the environment is causing him stress in some way, maybe there are chemicals in the air, candles, air fresheners anything that could dissolve into the tank, try and rule anything out which could cause harm to the fish tank environment.

      If not then perhaps he hasn’t fully healed, try him on peas again and if you are really concerned move him back to the hospital tank if it improves his swimming.

      hope this helps and good luck

      • Thanks, Lewis! How long should we wait to feed him? How long can these fish go without eating when they’re sick? It’s been quite a few days since he was last fed. He’s probably starving!

        • Hi again Coralina,

          They can go a few days without food, but try and offer him a little food each day, maybe try some bloodworms, tubifex or daphnia, feeding can really helps with sickness, even if its just a little.
          we would say to still offer him peas and maybe a little bloodworm every day or two days just to help him out a bit more.
          If he doesn’t eat, don’t worry, just remove the uneaten food so it doesn’t rot in the tank.

          Keep up with small water changes, perhaps add an airstone for extra oxygen, this can really help too.
          Other than this just keep doing what you are doing, keep the water quality clean and keep offering him food.

          If you become more concerned in the long run, then perhaps try an anti internal bacteria medication, this can sometimes fix it.

          we hope your betta pulls through, good luck!

        • Don’t feed bettas peas, use daphnia instead. Betta fish are carnivores and insectivores, and peas can do them more harm than good.

          • Hi Leigh, thanks for your comment
            we have had lots of experience over the years keeping and breeding bettas and have used peas and canned green beans to feed them with excellent results.
            yes you are right that bettas are more on the carnivorous side, and prefer meaty foods, but in truth nearly all fish are omnivores to a degree and we have found bloated bettas to benefit from being fed the occasional cut and sliced frozen pea or green bean.
            Although certainly not in high amounts, we have found that they do help with bloat and bowel movements in small doses.

            Daphnia is another good food recommendation as it is easy to digest.

  12. Hi, I have a tank with two goldfish and two ghost shrimp in. One of my goldfish seems to be displaying the symptoms of swim bladder disease and has been for about a week. I clean out my tank every two weeks, and it seems to be fine. My only worry is, if I don’t feed him for 48 hours, how am I supposed to feed my other fish and my shrimp who are perfectly healthy? I don’t want them to starve, but my other fish looks so ill, he just stays upside down all day and whenever he tries to swim he just floats back up like a balloon. Any help would be appreciated

    • Hi Amy, thanks for your comment
      your other fish and shrimp will be fine not eating for 2 days dont worry, they dont need to eat every day like you or I.

      you could also quarantine the affected fish using a breeder box, these float in the top of the tank and allow water to pass through, they are good for situations like yours, where you need to separate fish in the same tank.

  13. My shark fish is having red eyes & swimming in lower tank with swimming to opposite direction what should I do plz tell bsc I love her so much

    • Hello there, thanks for your comment,
      For now, we would suggest testing your water to see if there is anything wrong.
      You can do so with an aquarium test kit or by taking a sample of your water to your local aquarium store, and they will test it for you.

      The swimming around the bottom in the opposite direction sounds like a typical swim bladder issue, you can try feeding her some more veggie based foods like frozen peas or green beans which may help with gas or digestion, and could help her heal.
      For better clarity, you could also try and take a photograph or video of her and send it to our email address: speaktous@thegoldfishtank.com
      We may be able to diagnose the issue better this way.

  14. Hi there, i have a pearlscale goldfish who’s pretty big. we have another fish (idk the name the one with the big forehead) and he’s smaller. i also have three catfish but two others have died. my pearlscale doesn’t seem to be able to swim to the bottom of our 20 gallon but it seems he has fish bladder from eating from the top. what should i do feeding wise?

    • Hi Ella,
      This is really common in fancy goldfish, and is one of the reasons we prefer feeding them sinking pellets over floating foods.

      Sounds like he has swallowed air and is having difficulty in expelling it, which is one of the leading causes of swim bladder.

      Feeding frozen peas is a great way to combat this, as it is a natural laxative, and can help the fish to pass any air trapped in its stomach.

      Going forward, either try swapping out for a sinking food, or simply wet the floating food so that it sinks immediately.

      Hope this helps and best of luck with your fish.

  15. My Molly is about 5 years old.
    He is bloated and I believe it’s swim bladder.
    Have done partial water changes, all levels are good, added an extra aerator and have kept the temp 78-80 as everything I read states too. I have tried peas as suggested but no interest. I stopped feeding for the 2-3 days, day 1 now, and am treating as well with Melafix and stress coat. My big concern is he is bloated good and on his side and lays at the bottom. He does turn up and swim but definitely not feeling well. So what do I do now? Wait for the 2-3 days no food to pan out and see? Should light be off totally? I hate seeing him like this

  16. I have a 12″ Goldfish. (was a fair fish). About three or four weeks ago he began floating on his stomach. I separated him from the other fish. Did water change, put in salt and bacterial medicine. He would improve a few days and then start floating on his back/head down again. I have held off the food for a few days, fed him peas, etc. Took all the steps recommended. He improves after not eating for 2-3 days but if I give him a few peas again, he goes right back to floating almost immediately. Once the food is out of his system again, he improves. Any further recommendations?

  17. Hi All,

    A couple of weeks ago I went to the fish shop and saw an aquarium full of beautiful Orandas. Yesterday I ‘ve just bought one Panda Oranda since I saw that they were all ok & healthy in two weeks. Now this morning I noticed that it already started to lose balance. I didnt give it food and nothing yet. All parameters are fine and aquarium is well cycled and mature – (3 yrs running). Does anyone knows whats wrong please? This Panda Oranda is very active and agile and is in a 360 ltr aquarium with 2 plecos and few guppies. Temperature is 25 degree celcius. PH – 7.5, Water change 30% once every week.


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