Swim Bladder Disease in Goldfish (Causes, Symptoms, Treatment & Prevention)

The signs of swim bladder disease in goldfish are swimming in odd ways, swimming while upside down, or sitting at the bottom of the tank upside down.  

The disease is known medically as positive buoyancy disorder, but most fish keepers call it swim bladder disease. 

In this article, we are going to talk about ways you can help a goldfish with swim bladder disease feel better once more.  

What Is Swim Bladder Disease in Goldfish?  

Swim bladder disease is a disorder where the goldfish’s swim bladder does not function the way it should, thanks to a physical abnormality, environmental reasons, disease, or other undiagnosed reasons. 

You will notice that fish have a hard time staying in a good swimming position, and they cannot get themselves to ascend or descend in the water. 

What Causes Swim Bladder Disease in Goldfish?  

The swim bladder is also known as the gas bladder or air bladder. This develops in the goldfish when they are just an embryo, and it comes from an out pocket of the fish’s digestive tract.  

Most fish have two versions of the swim bladder. There is the anterior portion, which is near the head and covered up by tough tissue that does not allow its size to be modified. This particular bladder is attached to the spine, so it cannot change its position.  

The rear swim bladder is behind the anterior but is near to the tail. This swim bladder has a cover that is quite thin and can vary up its size depending on how much gas is in the swim bladder.  

The rear swim bladder is connected to the front swim bladder (anterior) via a tiny duct and can change its placement for many reasons. The anterior kidney pole is located between the anterior and rear parts of the swim bladder.  

Floating Food

The disorder may be caused when the swim bladder becomes compressed. This results in a stomach that is distended thanks to the fish eating fast, eating too much, being constipated, or taking in gulps of air, which may happen when the fish eats floating food such as pellets.  

Poor Quality Food 

 If the food for your goldfish is stale or low quality or not intended for goldfish, it could cause gas in the fish’s gut.  

An excess of gas can cause the fish to lose their balance. This gas will find its way into the swim bladder and cause the fish to become too buoyant.  

The fish also will have trouble releasing this gas.  

Eating flaked or freeze-dried food after it has become wet and expands could also lead to a stomach that is enlarged or even an enlarged intestinal tract.  

(Other food such as bread and bloodworms can also cause swim bladder disease.)

Sudden Temperature Changes 

Goldfish with round bodies, in particular, are susceptible to chills.  

Make sure your water temperature is where it should be for your goldfish. Having too low water temperature can slow down digestion for your fish, which leads to enlargement of the gastrointestinal tract, which puts the swim bladder under pressure.  

Having the correct tank temperature is just as important as having good water quality and nutritionally sound food for your fish to eat. Fish, whether in the pond, the wild, or aquarium, are quite sensitive to the changes in temps, and this can have a big impact on their immune systems.  

Your best bet is to choose the correct heating unit based on the size of the aquarium. Aim for 3 to 5 watts per gallon as your guide. A heater can only bring the aquarium up to a certain temp. So, you may need to add an extra heater if necessary in order to keep your fish in good health.  

For goldfish, this is rare unless you live in a VERY cold place and your home is not adequately heated. After all, goldfish like it cold.  

However, it may not be a bad idea to keep one on hand. After all, the temps in our environments and homes vary a lot during the fall and spring months, so keep a record of your tank temperatures as well as the temperature outdoors. This will help you set up heaters as necessary, depending on the season.  

(Find out more about whether goldfish need a heater.)

Diseases like ich can come about as a result of a fish having a suppressed immune system. If you notice it getting colder outside, gradually raise the tank temperature by one degree a day and vice versa for hot weather. This helps your fish adjust accordingly with minimal stress.   

Watch For Infections 

Bacterial attacks to the swim bladder can lead to loss of buoyancy and/or balance. 

Parasites are another problem that should be treated, as are bacterial infections. Keeping watch on the water quality of the tank and recording notes about how your fish look and act each day will help you stay on top of your fish’s condition. In some cases, the fish may develop a swim bladder disorder after hitting a tank object or being in a fight with another fish.  

You should also get swim bladder disease treated right away if you suspect something is wrong. Organs in the abdomen may become swollen and have a negative impact on the swim bladder.  

Organs like the kidneys can develop cysts, the liver may get fatty deposits, and egg binding could occur in female fish. These can all result in an enlarged swim bladder.  

In some very rare cases, fish are born with a swim bladder disease. However, these problems show themselves early on and are quite few and far between.  

(Other issues also include dropsy, constipation, fin rot, ich, and popeye.)

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Water Conditions 

The water quality of your tank matters. Having high nitrate levels, for example, can really affect the swim bladder. Nitrite happens when fish release ammonia via their gills as a waste product. The ammonia is then converted by good bacteria to nitrite, which is toxic for the fish. 

(Another problem that this can cause is ammonia poisoning.)

In aquariums that are cycled, other bacteria present in the fish tank will convert the nitrite to nitrate, which is harmless. However, new aquariums that are not equipped to detox the fish waste can lead to high ammonia levels. This leads to elevated ammonia, which leads to nitrate poisoning. You may even hear this referred to as Brown Blood poisoning.  

As for pH, keep it neutral around 7. Goldfish can live just fine in water that has pH 6-8.5, but if the pH is changed up too fast, they tend to get stressed out. A good water test kit will have you always in the know about the quality of your water.  

Make sure that your tank is always free of harmful water additives like chlorine and chloramine. Make sure you invest in a good water de-chlorinator, which you can get at your local fish shop or online, to keep the water suitable and healthy for your fish.  

 Perform water changes weekly to ensure the tank stays clean and waste-free.  

Swallowing Air 

Some fish keepers only feed their fish sinking pellets because of the belief that giving goldfish floating food will cause the goldfish to swallow air.  

Some fish are predisposed to swallowing air. Our goldfish personally haven’t done this, but you may wish to feed the goldfish sinking pellets exclusively to combat any chance the fish could end up swallowing air.  

Old Age/Genetics 

As the fancy goldfish varieties age, they tend to develop more problems with their swim bladder. Make sure you keep a close eye on how the fish swims. This will make it easier as you choose which varieties of fancy goldfish to breed or when it is time for you to thin out your brood of goldfish.  

What Are the Symptoms of Swim Bladder Disease?  

Curved Back 

If you notice a curve in the back of your goldfish, chances are they are struggling with swim bladder disease. The best thing to do is periodically examine your fish each day. Observe them as they go about their life in the tank- do this each day to identify anything out of the ordinary. 

Distended Belly 

Some goldfish have naturally round shapes, such as the Ryukin or Oranda. However, you have to be careful to look at the body of your fish closely. Monitor your fish each day to see if you notice anything out of the ordinary. A distended belly is a sign that swim bladder disease may be affecting your fish.  

Lack of Appetite 

If you drop in the food, and everybody rushes to get some except for your fish, this is a true sign that something is wrong.  

Floating at Top/Sinking at Bottom of Tank 

Do you notice your fish trying to swim correctly, but all they seem to do is float at the top or sink at the bottom? It is a hard thing to watch, especially for a beautiful goldfish. It is a tell-tale sign of swim bladder disease. 

How Do You Treat Swim Bladder Disease?  

Now, we will discuss how to treat swim bladder disease in goldfish. Here are the steps to follow: 

  1. Begin by knowing what to look for. When a fish has a swim bladder disease, the animal’s swim bladder has been compromised.  

Look for fish doing the following: 

  • Swimming belly up  
  • Sinking to the tank floor 
  • The tail is higher than the head. 
  • Distended belly 
  1. Know that goldfish are more prone to swim bladder diseases. Fancy goldfish especially tend to be more affected by swim bladder disease. The fancy types have round and short bodies, leading to compressed organs. The goldfish’s internal organs may push up against the swim bladder and make it hard for them to swim as intended. Meanwhile, goldfish with longer bodies are not at such a risk for developing swim bladder disorder as their organs are not packed as tightly. 
  1. Look for infection signs. Swim bladder disorder is a sign of infection, and if you suspect your fish has an infection, look for the following symptoms: 
  • The fish has clamped fins, has no appetite, and shakes; plus, other symptoms of swim bladder disorder are showing themselves. 
  1. You should first clean out the tank to lower levels of harmful bacteria. It is the first step in getting rid of bacteria that is causing an infection. If the symptoms persist in your fish, you may wish to treat the fish using a broad-spectrum antibiotic. These can be bought from your local fish shop or pet store. You may also wish to consult with a vet to get a prescription or recommendation. There are also medicated food flakes, and water treatment drops available, too. 

Make sure to follow all instructions carefully when using a medication, so you do not overmedicate the goldfish. 

  1. Make sure tank temp is where it needs to be. Goldfish are cold-water fish, fancy goldfish like water temps of 68F to 74F—meanwhile comets and shubunkins like temps of 60F to 70F. Having the correct water temperature will help your fish digest food properly. 

Fasting for Goldfish 

Swim bladder disorder may be caused by eating. When the organs of a fish become enlarged, they press on the swim bladder and may very well cause the fish to swim improperly. The stomach, liver, and intestines may also become enlarged thanks to the fish’s eating habits.  

The following may cause swim bladder disorder: 

  • Internal organ deformity 
  • Eating air-filled, poor quality foods (may lead to constipation) 
  • Taking in too much air while eating 
  • Kidney cysts 
  • Eating too much- can lead to fatty liver deposits. 

Since eating is a major cause of swim bladder disease, a three-day fast may be the way to help your goldfish out. When fish eat too much, they run the risk of enlarging their organs. Allow your fish three days to digest the food they’ve already eaten and let their organs shrink down to regular and safe size.  

  • Do NOT let your fish fast longer than three days.  
  • Make sure to record how your fish is doing- if the fish still doesn’t appear to be improving, try cooked peas.  

Cooked Peas 

Peas are a high fiber, dense food, and they can help a fish out who may be constipated. Get some frozen peas and cook them until they become soft. Now peel the outside of the pea off and put a small bit in the water. Limit the peas to one or two each day. 

Do not overcook the peas- the fish won’t be able to eat them if they are too soft (they fall apart).  

How Do You Prevent Swim Bladder Disease? 

Preventing swim bladder disease is actually easier than you think. Here are some ways to stop swim bladder disease in goldfish before it starts.  

Soak Food First 

Flake fish food floats on top of the water. It means when fish go in for a bite; they take in some air, too. It leads to the enlargement of the organs, which in turn leads to swim bladder disorder. 

You can prevent this by soaking the fish food first before you add it to the tank. This way, it sinks into the water, which allows the fish to eat safely with no worries about sucking in oxygen. 

You can purchase sinking fish food that sinks to the bottom of the tank, or you can offer frozen food that is nutrient-dense and thawed before you feed it. 

Avoid Overfeeding 

When fish eat too much food, they may end up constipated. It can lead to enlargement in the stomach or intestine and, of course, swim bladder problems. Feed your fish just once a day and only feed what the fish can eat within one minute. Even if your fish seems like it always wants to eat, eating too much is not healthy for the animal. 

Clean the Tank 

If you don’t clean your tank often, bacteria and parasites will become part of the water, which will make your fish sick. Be sure you clean your tank as needed or at least once per week. 

Set a reminder on your phone to clean the tank each week at a set time. Make sure you have a water test kit that shows you readings for pH, nitrite, nitrate, and ammonia. Goldfish are best at a pH of 7.2 to 7.6.  

They should have zero ammonia and nitrate of 0-.25 ppm. Aquarium salt is also an excellent supplement that will boost the immune system and fight illness in goldfish. 

Keep Records 

Record your daily readings in a notebook or Excel spreadsheet so you can easily notice patterns in your fish’s health and solve them before they get too out of hand.  

You should do this also for your fish’s appearance. Each day make a small note of what they look like and how they are acting. It helps you keep track of their behaviors and make any necessary changes. 

Is Swim Bladder Disease Contagious? 

Swim bladder disease is very common, but the good news is that the disease itself is not contagious.  

It is a symptom of greater health issues and is not a standalone condition. As we have learned, it may be the result of not eating properly, eating too much, or taking in air while eating. 

Getting swim bladder disease does not result from fish nipping or biting at one another. Instead, it mostly results from the compression of internal organs or infection.  

For example, aquarium fish such as goldfish may contract infections that come about as a result of bacteria and parasites that are found in their tank water.  

These parasites and bacteria are contagious thanks to all the fish sharing the same water, but the disease itself is not. Remember, swim bladder disease is a symptom of something greater; in this case, it is the infection caused by the unclean water. 

You can absolutely prevent swim bladder disease from happening to your fish. Make sure your fish tank is kept clean, and be sure to perform regular cleanings each and every week.  

Do not overfeed the fish, and if you do, scoop out the excess food as best you can. Thankfully, this is a disease you don’t have to worry about with proper preventative care. 

Is Swim Bladder Disease Fatal?  

Swim bladder disease is not fatal when it comes to aquarium fish. This is no doubt a relief to many fish keepers, especially those with fancy and hard-to-find goldfish. That being said, the experience of contracting such a condition is not fun for the fish. 

After all, just look at some photos of fish that have contracted swim bladder disease. Can you imagine having to live your entire life upside down or at an angle? It would definitely mess with your field of vision and leave you feeling very uncomfortable and frustrated that you couldn’t live your life as you always do. 

The disordered fashion in which the fish floats is often caused by the posterior chamber becoming overinflated. With goldfish, they may not even have a posterior chamber.  

Overinflation can also come about as a result of some uncomfortable ailments such as trauma, cancer, or even parasites. Gas displacement can also cause your fish to swim improperly. Fish can very well swim on their side thanks to a shift in the air in their body. 

Goldfish are more prone to this disease than others. As goldfish enthusiasts, we have to realize that this disorder is very preventable simply by making tank cleanings a regular weekly task, keeping the tank a healthy temp, and feeding just enough food. 


We hope this article has been helpful for you in figuring out how to keep your fish feeling healthy and avoid swim bladder disease in goldfish. The best thing for you to do is keep the tank clean and neat and feed appropriately.  

These two actions will keep your fish feeling good and swimming normally. Now that you know how to get rid of swim bladder disease go check out our other helpful fish care articles. You will know what to do the next time you encounter a problem with your fish and handle it with confidence. Good luck and happy fishkeeping!