Swim Bladder Disease in Betta Fish: Symptoms, Treatment, and Prevention

Swim Bladder Disease in Betta Fish
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If you notice an awkward swimming pattern in your bettas, it could be a symptom of swim bladder disease.

It’s a common distressing condition in betta fish that makes it challenging to swim normally.

Swim bladder disorder is not an illness but a manifestation of other ailments and conditions.

Bettas affected by swim bladder disorder usually stay floating upside down and struggle to remain on the water’s surface.

Swim bladder disease is rarely lethal. It’s also easily treatable and preventable.

So, if your betta fish suffer from this disorder, there’s nothing to panic about.

Just read this post to the end to learn about the causes and symptoms of swim bladder disease and what treatment method you can apply to cure it.

You’ll also learn how to prevent swim bladder disorder in your bettas.

What is swim bladder disease in bettas?

Swim bladder disease, sometimes called swim bladder disorder, is usually a pseudo-disease that is a secondary symptom of other illnesses in betta fish.

It causes the swim bladder of your betta fish to compress, due to which they can’t control their buoyancy in the water.

The swim bladder is a unique buoyancy-regulating organ in most bony fish species. It’s located in the abdominal cavity of betta fish.

The swim bladder is filled with oxygen gas and acts as a ballast organ that allows fish to regulate buoyancy.

When the swim bladder gets compressed under the effect of swim bladder disorder, your betta fish can’t adjust their buoyancy.

When a betta suffers from swim bladder issues, you’ll notice them floating upside down, lying on the bottom of your aquarium, and sometimes floating at the top.

With this, they spend more energy getting to other parts of the aquarium.

What causes swim bladder disease in bettas?

Any ailment or condition that can cause the compression of the swim bladder can be a cause of swim bladder disease.

Here are some common and potential causes of a swim bladder disorder:

Digestive issues

Digestive issues, such as overfeeding or constipation, are the common causes of swim bladder disease in bettas – and I was once guilty of this.

When your betta overeats, her stomach becomes so swollen that it starts pressing the walls of the swim bladder inside, which produces compression in the swim bladder.

This compression could lead to constipation and then swim bladder disease.

Digestive problems usually occur if you feed pellets, flakes, or freeze-dried foods.

If you’re feeding these foods, they will expand and cause blockage in your bettas’ intestinal tract and/or stomach.

This will cause swim bladder issues as it presses against your betta’s body.

However, this doesn’t mean you should not feed them pellets or freeze-dried food.

It just means that there are precautions you should take if you’re feeding them this – which I’ll cover later in this post.

Bacterial or parasitic infection

A bacterial or parasitic infection is one of the least common causes of swim bladder disease.

It happens when parasites or bacteria attack the swim bladder of betta fish and cause it to become swollen.

As I mentioned, swim bladder disorder usually comes as a secondary issue.

Suppose your betta faces other bacterial or parasitic diseases such as anchor worms, popeye, ich, or my worst enemy – velvet.

As such, there is a slight chance it might affect your betta’s swim bladder.

In some cases, parasites embed in the walls of your betta’s swim bladder and produce pores, which causes leakage of oxygen gases.

In such a situation, your betta may lose control of inflating and deflating the swim bladder, which could lead to buoyancy problems.


One of the most causes of disease in betta fish is a shock. Sudden changes in your aquarium’s water parameters can trigger shock and stress in your betta fish.

When (all) fishes are shocked; their immune systems are compromised, making way for many diseases, such as swim bladder issues.

That’s why it’s important to acclimate your betta to new water conditions, even if it’s a hospital/quarantine tank.

Low water temperature

Betta fish – especially wild bettas – are one of the most temperature-sensitive fish species.

They can feel minor changes in their aquarium. The body systems of betta fish function optimally when the water temperature is between 25 to 28º Celsius or 78 to 82º degrees Fahrenheit.

Most bettas such as betta splendens, betta mahachai, betta smaragdina (and many others) can live comfortably in higher temperates – as seen in many aquariums kept by Southeast Asian hobbyists.

For these bettas, their digestive system can slow down and cause swim bladder disease when the temperature falls below their preferred range.

However, not all bettas prefer higher temperatures. Many mouthbrooding species – depending on localities, such as betta albimarginata, betta rubra, and betta channoides – prefer colder waters.

Other mouthbrooders living deep in rainforests and hill streams, such as the betta macrostoma, prefer exclusively cold water.

I’ve read many incidents whereby betta macrostoma would jump out of their aquariums if it’s not cold enough.

So it’s essential to know more about where your betta lives in the wild so that you can provide the best environment for them.

This is critical to prevent diseases such as swim bladder disease.

Physical injury

Any physical injury or trauma that can damage your betta’s swim bladder can be the cause of the swim bladder disease.

Your betta may sustain a physical injury in her gastrointestinal region in a fight with a tank mate or by striking with your aquarium decorations.

This could lead to the compression of her swim bladder.

Betta fish may also sustain physical trauma by jumping out of the aquarium during maintenance.

Although it’s pretty uncommon, the possibility of swim bladder disease due to injury cannot be ruled out.

Birth issues

A betta fish born with an impaired swim bladder due to birth defects could develop swim bladder disease at any time during her life.

Many say double-tail betta fish are more prone to birth defects that can cause swim bladder disorder.

Besides these causes, egg binding in female bettas and cysts in the kidneys of betta fish can cause swim bladder disorder.

And if this is the case with your betta fish, there’s nothing much you can do except wait and take good care of them.

An alternative is to euthanise them.

Ammonia Poisoning

Lastly, one of the most common reasons why your betta might face any form of disease is due to ammonia poisoning.

Again, it’s unlikely a direct cause of swim bladder, but the stress caused by ammonia poisoning is a prequel to any disease that might cause swim bladder disease.

Symptoms of swim bladder disease

Betta fish suffering from swim bladder disease can show many symptoms – of which you may not notice all of the symptoms simultaneously.

In most cases, the symptoms that betta fish display depends on the cause of the swim bladder disease.

For example, suppose your betta fish have developed swim bladder disorder due to overeating or constipation. In that case, their symptoms will differ from bettas suffering from swim bladder disease due to parasitic or bacterial infection.

There’re also some common symptoms displayed by almost all fish suffering from swim bladder disease. Most of these symptoms are related to the ability of fish to swim and remain buoyant in the water. These symptoms include:

  • Floating to the top of the aquarium
  • Sinking to the bottom of the aquarium
  • Unnatural swimming patterns (such as swimming upside down, vertically, or sideways)

You may also notice a curved s-like spine in your betta fish. A swollen abdomen can also indicate swim bladder disease – though it could just be a deformity.

Symptoms of swim bladder disease caused by overeating or constipation

When your betta fish is suffering from swim bladder disorder due to overfeeding or constipation, you may notice the following symptoms in them in addition to the common symptoms:

  • Lopsided swimming
  • Inability to maintain the normal position
  • A distended belly
  • Lack of appetite
  • Lethargy

Swim bladder disease disturbs the gas balance in the swim bladder of betta fish, due to which they lose control of their position in the water tank.

They may lose their appetite or remain unwilling to eat longer.

You may notice that your bettas struggle to eat their food, especially when they sink to the bottom of the aquarium. Lethargy can be a significant sign of swim bladder disease.

Symptoms of swim bladder disease caused by parasitic or bacterial infection

If your bettas are suffering from swim bladder disease due to parasitic or bacterial infection, they may display the following symptoms:

Clamped fins

One of the classic signs of a parasitic or bacterial infection in your betta is clamped fins.

When your betta fish have compressed swim bladder, they become stressed, and one of their ways to express their stress is to keep their fins close to the body.

If you notice clamped fins in your bettas, don’t go for the treatments for overeating or constipation, as they may not be effective in alleviating the condition.


I’m not sure how a betta fish can shiver, nor have I seen it happen before, but some online resources mention that shivering could cause swim bladder disease due to parasites or bacterial infection.

Sources say if you notice that your betta fish is shivering, it indicates that your betta is suffering from parasitic or bacterial infection.

Stringy pale poop

You can identify swim bladder disease caused by bacterial or parasitic infection by examining the faeces of your betta, which will be stringy and pale in colour.

Treatment of swim bladder disease in bettas

The treatment method you must apply to your betta fish depends on its cause.

The treatment method for swim bladder disease caused by overfeeding will differ from the swim bladder disease caused by a parasitic or bacterial infection.

So make sure to identify the correct symptoms before treating them.

Treatment of swim bladder disease caused by overeating/constipation or other gastrointestinal problems

If your betta fish is suffering from gastrointestinal or digestive issues, like overfeeding or constipation, you need to follow this treatment procedure to speed up its recovery:

Take a quarantine tank, fill it with the water from your betta’s tank, and shift your betta to this quarantine tank.

Keep your betta fish in the quarantine tank for three days without food. Don’t be worried about them being hungry. They do this in the wild, so it’s not an issue.

During these three days, gradually raise the temperature in the quarantine tank until it reaches the 80°F (27ºC) mark.

If you’re keeping them in higher temperatures, you can raise the temperature to 33ºC (92ºF) max. Any higher and it’ll be uncomfortable for them.

Increasing temperature boosts your betta’s metabolism and helps them digest the food it previously ate quickly.

When your betta fish have their three days in the quarantine tank, it’s time to check for any improvement.

If you notice that your bettas are no longer showing the symptoms of swim bladder disease, the treatment has proved effective. You can shift your bettas back to its aquarium.

However, if your betta fish still have its symptoms, keep them in the quarantine tank and begin feeding boiled peas and/or daphnia, which are rich in fibre.

Treatment of swim bladder disease caused by parasitic or bacterial infection

If your betta fish show parasitic or bacterial infection symptoms, the treatment will remain similar, except you use medication instead of making them fast.

You can follow the following steps:

Transfer your bettas to the quarantine tank so you can treat the aquarium water with medication.

If your bettas are suffering from bacterial infection, you should use an antibiotic medication such as Melafix to kill infectious bacteria in the aquarium.

However, if you think it’s a parasite that has caused infection in your betta fish, you should use an antiparasitic medication such as Seachem ParaGuard.

  • Treat your aquarium’s water as per the instructions printed on the medicine’s label.
  • Monitor the improvement in the symptoms of swim bladder disease in your betta daily.
  • Add the appropriate amount of Indian almond leaves to your tank.

Infections caused by parasites or bacteria rarely cause swim bladder disease in betta fish.

However, if you see any signs of infection in your bettas, you should not take a risk as this is a matter of their health.

Epsom salt treatment

Bathing your bettas in Epsom salt solution can often be an effective way to cure swim bladder disease.

Follow these directions to give an Epsom salt bath to your bettas.

Take 500 mL of conditioned tap water in a small container. Mix a small amount of Epsom salt (1 tablespoon) in it.

Shake/stir the water to ensure all Epsom salt has dissolved completely.

Once the Epsom salt is dissolved, take half a gallon (~4L) of your aquarium water and add it to the container to match the temperature and water parameters.

Bathe your bettas for 10-15 minutes in the container. After the Epsom salt bath, keep an eye on your bettas.

If they’re excreting and swimming normally, it has worked. If that’s not the case, you can consider bathing them again but for only 3-5 minutes.

If your betta fish suffer from swim bladder disease due to shock, I don’t think there’s much you can do apart from waiting it out.

I’ll add Indian almond leaves, maintain stable temperatures, and turn off the lights.

This reduces the stress/shock they feel, and turning off the lights lets them rest to recover faster.

How to prevent swim bladder disease in bettas

Follow these valuable tips to prevent swim bladder disease in your betta fish:

  • Always feed your bettas with high-quality food. Make sure the food you feed has proper nutritional content. Read my betta feeding guide here.

I like using PRO-FEED, which I think is only available in Singapore, and Dr. Bassleer Biofish Food with Garlic.

Garlic has been known to prevent and treat diseases in bettas while encouraging them to eat pellets.

  • If you’re feeding pellets, flakes, or freeze-dried food, don’t forget to soak the food before feeding.

Soaking the food will cause it to expand. This makes your betta eat lesser and prevents overeating that may cause the food to expand internally.

  • Avoid overfeeding as it can cause swelling in the stomach, which could lead to swim bladder disease.

I feed 2 to 3 pellets daily, depending on the pellet size.

  • Maintain high-quality water in your aquarium.

Test your aquarium for ammonia, nitrate, nitrite, pH, gH, and kH levels, especially for more sensitive bettas.

I suggest buying the API Freshwater Master Test Kit. Totally worth every penny.

  • Keep the aquarium’s temperature constant.

Buy a digital thermometer to keep track.

  • Don’t keep your bettas with aggressive tank mates.

This prevents fighting and damaged internal and external organs that may cause diseases.

  • Remove any decoration elements or ornaments that can cause physical injury to your bettas.

Any sharp objects, such as fake plants or sharp rocks, can cause physical injury.


While swim bladder disease has many causes, such as overfeeding, constipation, infection, or shock, it’s easily treatable and preventable.

You need to identify the cause and apply a suitable treatment method.

Swim bladder disease hardly proves lethal, so you should focus on prevention and treatment instead of panicking.

Remember, prevention is always better than cure, so always take the extra step to prevent diseases.

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