Bloated Betta: 3 Primary Causes Of Bloatness In Betta Fish

Bloated Betta
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Last Updated: July 13, 2022 by Flora Gibbins

Though betta fish are resilient by nature, they’re still prone to various health issues if you aren’t careful enough with their diet and the cleanliness of their tanks. One of the most common betta fish illnesses has to be bloating.


Such an issue might sound trivial, but it can be life-threatening to your beloved betta as bloating can impair its swimming ability. In addition, your pet fish can get stuck at the bottom of the tank, preventing it from resurfacing to breathe.

Don’t worry, though; we’ve gathered all you need to know about bloated betta fish, giving you tips on how to avoid such an issue and ways to tackle a bloated belly and treat constipation!

Red Flags for a Bloated Betta Fish

Before deep-diving into the many bloated betta symptoms, we figured it’d be useful to highlight some of the most prominent signs of a bloated betta that even the untrained eye can pick. That way, you can anticipate the issue before it gets out of hand and helps your favorite betta regain its health in no time. 

So, always be on the lookout for the following red flags:

  • Your betta’s stomach can appear enlarged and projecting to one side more than the other. This gives your fish an asymmetrical look that instantly gives away the underlying issue.
  • The swollen stomach of a female betta fish can be mistaken for an egg-bound tummy. So, unless the bloated stomach coincides with the male betta fish enclosing some eggs in a bubble nest, you can exclude that the fish’s body changes are due to the eggs.
  • Any sudden changes in your betta fish’s activity, in addition to obvious trouble swimming.

Poor water quality, bacterial infection, and parasites residing in the fish’s digestive system are some of the most common causes of a betta fish’s bloated belly.

Furthermore, any compromise to the fish’s immune system provides the perfect condition for bacterial infections to go unchecked and impact the health of such freshwater fish.

What Causes Bloat in Betta Fish?

Pinpointing the cause of bloat in betta fish can be quite challenging at times since several conditions contribute to causing a swollen tummy. Each condition requires different considerations when it comes to treatment, so it’s always useful to identify the exact etiology.

By far, the most common cause of bloat in betta fish is constipation, followed by swim bladder disease. 

This is great news for pet store owners, as such conditions are fairly easy to treat. Unfortunately, dropsy takes third place and comes with a great toll on the betta’s internal organs, making recovery a bumpy road. 

Let’s break down the different causes of betta fish bloating and walk you through what you need to do to guide your buddy back to its healthy state.


Fortunately, the most common cause of betta fish bloating is the easiest to treat. Though severe constipation might present some alarming symptoms, your betta pal should fully regain its health shortly after, provided you follow a sound treatment plan.



  • Poor diet: Constipated fish are usually the end result of an unbalanced diet. Nutrient-dense meals can pose a challenge to the betta’s delicate digestive system. Also, a diet that lacks sufficient fibers proves to be the prime cause of bloating.
  • Poor appetite: Betta fish are notoriously known for their wild appetite. Your fish is always hungry and can eat whatever comes its way. So, ensuring your betta gets its fair share of daily meals should be prioritized. If you keep your fish pal hungry for a long time, it might start eating pebbles or other items in its tank, leading to serious constipation and obstructed bowel movement.
  • Lack of physical activity: The betta’s digestive tract consists of smooth muscles that require exercise to remain healthy and active. So, your fish needs to maintain a considerable level of physical activity and constantly swim around its tank. You might be doing your betta fish injustice if you’re keeping it in a small tank with a bunch of tank mates, where each fish doesn’t have enough space to actively swim around and explore its environment.


  • Swollen tummy: This might limit the betta’s swimming capacity and causes trouble breathing.
  • Changes in appetite: Bettas require a steady stream of food all day long to keep up with their appetite. So, if you notice that your betta pals suddenly stop eating, you could quickly suspect that something isn’t quite right. This is especially evident if you’re maintaining the same high-quality food your betta is used to, but still, your fish abstains.
  • Less waste: Naturally, a constipated betta will have a hard time passing stool. This might present itself in the form of stringy feces, but admittedly, they’re hard to spot for the untrained eye due to the fact that bettas don’t normally produce tons of waste daily.

Swim Bladder Disease

As its name suggests, swim bladder disease is a condition caused by the betta’s swim bladder dysfunction. For the uninitiated, this system is responsible for the fish’s buoyancy and ability to move freely underwater.



  • Unhealthy eating practices: Overfeeding, constipation, air swallowing, and quick eating are all related to swim bladder problems. This is because they all share in unduly expanding your betta’s stomach, pressing on the swim bladder system, and limiting its capacity.
  • Granular flake food: Unlike live food, dried and granular flake food expands upon becoming wet. As the food resides in the betta’s stomach, it keeps expanding over time, leading to a swim bladder disease.
  • Water temperature changes: Any sudden changes in the water’s temperature, lighting conditions, or pH can contribute to the swim bladder disease. Betta fish are really sensitive to any changes in their surrounding environment, and they can’t tolerate sudden fluctuations. Furthermore, cold water slows down the fish’s digestion process, which means food will stay for longer periods in the betta’s digestive tract and press on the swim bladder.
  • Other underlying illnesses: Betta fish gut is an enclosed space that maintains a specific pressure level. So, any expansion to the fish’s internal organs comes at the cost of pressing on the swim bladder. For instance, pregnancy, kidney cysts, and fatty liver are all conditions where the internal organs occupy more space and cause swim bladder disease.
  • Injuries: Finally, your betta fish might injure itself and end up with a swim bladder dysfunction. For example, it’s always recommended to cover your betta’s tank so it doesn’t feel adventurous, and try jumping out of it. Also, you need to avoid aggressive tank mates that keep nipping at your fish and potentially damaging its swim bladder system.


  • Buoyancy changes: The key symptom of swim bladder disease is the disturbance of the fish’s intrinsic buoyancy system. You might notice that your betta fish is having difficulty navigating its tank and might get stuck at the surface or the bottom. This can be a serious issue, as your betta needs to constantly reach the surface to breathe.
  • Curved back: In some extreme cases, the swim bladder disease might present with some physical changes to your betta fish in the form of a curved back.


Unlike constipation and swim bladder disease, dropsy is a challenging condition to treat and usually brings an end to your beloved betta’s life. You also need to remember that any affected fish should be kept in a quarantine tank to prevent the spread of the illness to their other tank mates.



  • Bacterial infections: Dropsy is caused by a bacterium that penetrates the betta’s scales and quickly spreads to the kidneys and liver. Once such organs are affected, the body can’t get off excess fluid, and the fish develops edema and bloating.


  • Changes in activity and eating patterns: The accumulation of fluids brings drastic changes to the fish’s swimming ability and appetite.
  • Pinecone scales: Betta fish with dropsy has a pinecone appearance as their scales stand out and give a bumpy look. Such physical changes are due to the damage to the fish’s internal organs that causes the fish to bloat and push the scales to protrude outwards.

Factoid: One tell-tale sign your Betta could be experiencing tummy trouble is it spits out food it takes! Learn about this odd behavior by reading Betta Fish Spitting Out Food: Tummy Problems Reveal & Cure to aid you in detecting tummy disorders in your betta pal.

How to Prevent Betta Fish Bloating

Ensuring your betta fish maintains a healthy immune system should be your prime concern for preventing bloating. This can be achieved by avoiding poor diet, poor water quality, and overcrowding.

Tank Size

Tank Size

For starters, you need to make sure your betta inhabits an adequately sized tank and has the freedom to wander around and maintain a healthy activity level. In addition, it’s recommended to keep your betta fish within tank water of ten gallons or more to avoid any constipation-related issues.

Tank Mates

Tank Mates

If your betta fish is sharing a community tank with other fish varieties, you need to ensure that your buddy isn’t under any kind of stress. 

Sometimes, aggressive tank mates can be the reason for your betta fish’s health detriment.

So, why keep your beloved betta with aggressive tankmates in the first place? The demand for vibrantly colored betta fish is skyrocketing, and making experimental pairings is one of the ways pet shop owners can breed more beautiful fish with unusual colors.

Such experimentation factor comes with underlying genetic deficits that contribute to betta fish bloating. Also, the stress bettas might have to endure during the reproductive cycle can bring a huge toll on their overall health and the well-being of their digestive tract.



Next up is ensuring the high quality of your betta’s diet. Without delving into the different fish food brands that you can get from your local pet stores, we have a quite simple recipe for your fish pal that you can easily prepare at home. 

Peas represent a well-balanced diet for betta fish, and they’re readily available in most households, making planning your betta fish’s meals less of a hassle. All you need to do is submerge one pea in boiling water for 30 seconds- 1 minute, depending on whether you’re using fresh or frozen pea.

Then, you need to transfer the pea to a cold basin and leave it to chill. Now, it’s time to remove the pea skin, and voila, you’ve got an easy, delicious meal for your betta finish in under a couple of minutes.

Salt Content in Water


The tank water’s pH is a key determinant in the betta fish’s health.

Therefore, your fish pal needs low-level salt baths comparable to its blood salinity to maintain a healthy osmotic balance. This way, the fish never develops fluid retention, and dropsy should no longer be a concern.

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Frequently Asked Questions

How to treat swim bladder disease?

To treat swim bladder disease, all it takes is to fast your betta for a few days and then offer high-quality dried or live food. You can also add some aquarium salt to your fish’s tank or do an occasional Epsom salt bath to maintain the health of the swim bladder system. Finally, some over-the-counter medications might be the solution for swim bladder disease.

How to treat dropsy?

Adding antibiotics and antibacterial agents to the water comes with questionable efficacy as some bacteria are hard to kill.

Furthermore, methylene blue dips can be considered a second line of treatment worth trying when antibiotics fail. However, remember that prevention is always better than cure, so changing your betta’s water frequently shouldn’t be overlooked.

What is a Malawi bloat?

It’s a rare condition that usually affects other fish species but can be occasionally seen in betta. It’s caused by mosquito larvae and a variety of bacterial diseases. The best way to prevent it is to keep your fish’s water clean.


Betta fish bloating is a fairly common condition that shouldn’t be a cause of concern as it’s easily manageable. However, once you notice any signs of bloating, it’s always recommended to move your diseased betta to a separate quarantine tank.

Its stringy stool can be a means of transferring the infection to other fish; hence, it would lessen the spreading of the disease if the affected fish is moved to a separate tank. Moreover, the bacteria will cling to your aquarium accessories and eventually compromise your filtered aquarium water.

Finding a remedy to your bloated betta is easy as long as you follow these tips: (1) learn more about your pet fish, (2) reach out to a professional fish breeder for advice, and (3) seek medical assistance from a reputable veterinarian.

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