Bloated Betta: Symptoms, Causes, Treatment & Prevention

It can be scary when you turn your tank light on one morning and notice that your betta fish is bloated. The worst may start to run through your head, that it’s dropsy, and now the chances of your betta surviving are very slim. However, there are many different causes of betta fish bloat, and the majority of them are treatable.

Key Takeaways:

  • Betta fish bloat can have various causes, and it’s important to identify the symptoms and treat them promptly.
  • Common causes of bloat in bettas include constipation, swim bladder disease, dropsy, Malawi Bloat, tumors, and egg production.
  • Constipation is a leading cause of bloat and can result from a poor diet and lack of exercise. Fasting the betta for 2-3 days and then feeding with daphnia can help treat it.
  • Preventive measures for bloat in bettas include maintaining good water quality, offering a varied and nutritional diet, avoiding aggressive tank mates, sharp objects, and using an adequately sized tank.

What Are The Symptoms Of Betta Fish Bloat?

When your betta fish is bloated or swollen you’ll notice that his belly begins to protrude out. While this in itself can be hard to diagnose, in most cases, when there’s something wrong there’ll be other symptoms too.

So here are the causes of betta fish bloat, their symptoms, and how to treat them!

Betta Fish Bloated? What Are The Most Common Causes

The most common cause of bloat in bettas is constipation, followed by swim bladder disease, and unfortunately after that dropsy. If your betta has the first two, then he can often make a speedy recovery. But if he’s suffering from dropsy then the chances of survival are a lot slimmer.

Key TopicCausesSymptomsTreatment
ConstipationPoor diet, lack of exerciseBloating, lack of appetite, can’t pass stoolFasting for 2-3 days, then feed daphnia
Swim Bladder DiseaseInjury, constipation, water fluctuationsBuoyancy issues, sinking, lopsided swimmingFasting, Epsom salt, rest
DropsyPoor water quality/diet, illness, internal damagePinecone scales, curved spineDifficult to treat, frequent water changes, antibiotics if bacterial infection
Malawi BloatParasites, bacterial infection, stressTrouble breathing, bloating, lack of appetiteFatal in most cases, consult a vet
TumorRare occurrenceBloatingUsually fatal, euthanasia
Producing EggsNatural for femalesBloating, white stripes, white spotNormal occurrence in females

1. Constipation

If your betta is suffering from constipation, treatment and prevention are incredibly easy. Luckily this is the most common cause of bloat in bettas, so the chances are your betta will be suffering from this. As well as noticing a bloated belly, you may also notice the following.

Symptoms Of Constipation

If you think that your betta is suffering from constipation here are some of the main symptoms that can also occur with a bloated belly.

Lack Of Appetite

Bettas are extremely gutty fish, so you’ll notice he’s not eating in no time. It’s rare that bettas ever fill full, but one time they do is when they’re constipated. If you notice your betta isn’t eating anymore then this is the first indicator of constipation.

Can’t Pass Stool

This can be harder to spot, but if you can keep an eye on your betta, you may notice that he’s not able to defecate. This is one of the best indicators of constipation in bettas, and if you notice this in combination with a lack of appetite, then you should begin treating your betta for constipation!

Causes Of Constipation

There’s more than one thing that can cause constipation in bettas. So you should find out how to prevent it, instead of learning how to treat it! Here are the most common causes of constipation.

Poor Diet

If you’re feeding your betta too much, or if the food you’re feeding him isn’t high quality, then it can often result in constipation which leads to bloating. When feeding your betta you should be using a mix of high-quality fish pellets as well as live food too. If you can’t get your hands on live food then freeze-dried and frozen also work.

(Here are the best foods and best live foods for your betta. Also, find out whether your betta can eat goldfish food.)

Fluval Bug Bites Tropical Fish Food, Small Granules for Small to Medium Sized Fish, 1.6 oz., A6577
  • Tropical fish food that contains up to 40%, nutrient-rich Black Soldier Fly Larvae, the first ingredient
Lack Of Exercise

This cause is often overlooked, but if you’re keeping your betta in a small tank (anything below 5 gallons) then he may not be getting enough exercise. If this is the case, then it can often lead to constipation as well as frustration, boredom and even depression!

How To Treat Constipation

Treatment of constipation is incredibly simple and will require little work on your part. Normally fasting your betta for 2-3 days is enough to get their bowels moving again. However, on top of this, after 2-3 days you should begin feeding your betta small animals such as daphnia, mosquito larvae and brine shrimp. This will help him get more fiber into his digestive system which in turn will relieve his constipation.

If this treatment doesn’t work you can also give him Epsom salt baths and feed him peas.

If you think that your betta is suffering from constipation then this article will give you more in-depth knowledge about everything you need to know.

2. Swim Bladder Disease

If it doesn’t seem like constipation then it could be caused by swim bladder disease. However, swim bladder disease can be caused by constipation, and constipation can sometimes be caused by swim bladder disease (confusing I know). Because swim bladder disease isn’t actually a disease. It’s a name given to a multitude of things that can cause similar symptoms in bettas (and other fish).

Symptoms Of Swim Bladder Disease

There are many different symptoms which are associated with swim bladder disease. However, luckily, they’re incredibly easy to spot and once you’ve seen them you can begin helping your betta recover.

Any Trouble Swimming

If you notice any sign of your betta struggling to swim alongside a bloated belly, then swim bladder disease could be to blame. This can include, buoyancy issues, sinking to the bottom, staying stuck at the top, lopsided swimming and being unable to stay in one position. Trouble swimming is one of the most classic signs of swim bladder disease. It’s distressing to watch, but luckily in a lot of cases, it’s also curable.

Lack Of Appetite

Just like with constipation when your betta is suffering from swim bladder disease it could cause reduced appetite. This could be because they are extremely damaged, or caused by other factors.

(Find out all the reasons your betta fish isn’t eating, and what to do!)

Curved Back

In more extreme circumstances your betta could also begin to get a curved back. A curved back can often look horrifying and if you see it you’ll need to act quickly to get your betta back on the mend, as it’s going to be as uncomfortable as it looks.

(However, depending on the type of curve it could also be constipation.)


Lastly, if your betta doesn’t try to move around anymore and just stays in one place then it’s another sign of swim bladder disease. This could be because they’re too full up, or it could also happen when they’re in pain.

(Find out some of the most common betta behaviors before death.)

Causes Of Swim Bladder Disease

One of the biggest problems with swim bladder disease is that there are so many different reasons it can occur. Before you can treat it, you’ll need to know all the causes and diagnose it correctly, otherwise, you could just be wasting time. Here are some of the most common causes.


While bloating can be caused by swim bladder disease, swim bladder disease can often be caused by constipation. If you notice your betta fish is bloated and struggling to swim, then constipation could be the cause.


Another common cause of swim bladder disease in bettas is an injury. This can be caused by other tank mates which are being aggressive, or by your betta damaging himself on something in the tank. Swim bladder disease often happens if your betta has managed to jump out of the tank and damaged himself when landing.

Parasites & Bacterial Infections

Although, it’s rare sometimes parasites and bacterial infections can cause swim bladder disease in bettas. Along with these symptoms, you may also notice your bettas stool is a different color. Often appearing stringy and white, rather than brown.

(Check out the most common betta diseases and illnesses.)


There are various things that can cause shock in your betta including temperature changes, pH changes and constant changes in lighting. If you think your betta is in shock, fixing the underlying issue will normally fix the swim bladder disease as well.

How To Treat Swim Bladder Disease

There are many different ways you can treat swim bladder disease, and in some cases, no care from you is required. The most common ways to treat swim bladder disease are by fasting your betta if he’s been overeating, using Epsom salt if he’s constipated, and leaving him if he’s shocked.

If you want to know more about swim bladder disease and how to treat it effectively then this article is going to teach you everything you need to know!

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3. Dropsy

If it doesn’t seem like constipation or swim bladder disease, then, unfortunately, it could be dropsy. If it is dropsy the chances of your betta surviving are incredibly slim. While some fish have made a recovery from dropsy in most cases, euthanasia is the most likely option you’ll need to consider.

Symptoms Of Dropsy

If your betta fish is bloated and you think it’s dropsy, then there are also some other symptoms you can look for. While some of them can be caused by other ailments, one of them is unique to dropsy.

Pinecone Scales

If you notice that your bettas scales are sticking out the wrong way (making him look like a pinecone) then it’s dropsy that he’s suffering from. Unfortunately, at this stage, the chances of survival are incredibly slim.

The pinecone effect is caused when the organs are so damaged they begin to swell, forcing your bettas body to bloat and pushing his scales out. Even if you fix the original problem, the organs are normally too damaged for survival.

Curved Spine

You may also notice that your bettas spine is curving outwards as the swelling causes more damage. However, make sure that the spine is curving sideways and not vertically, as this is a sign of tuberculosis.

Causes Of Dropsy

It can be hard to pinpoint the exact cause of dropsy as there are a wide variety of causes. However, most of the time it’s some sort of stress that your betta is going through that causes it to occur. The most common reasons your betta will be stressed are the following.

Poor Water Quality/Diet

If you’re keeping your betta in a tank with poor water quality or you’re not feeding him properly then he’s more likely to get dropsy, as well as a whole range of other illnesses. Poor water and food will put constant stress on your betta weakening him and damaging his immune system until he can’t fight any illness off.

Internal Damage

Bringing your betta home for the first time, moving him around, fighting, or dangerous object in your tank can all cause internal damage to your betta which you may not see on the outside. If the damage is too severe, then his organs and tissue will begin to swell to try and heal him. Unfortunately, this doesn’t work and your betta is left with dropsy.

Illness & Disease

If your betta is already suffering from an illness it’s even more likely that he’ll develop dropsy. This is one of the reasons it’s vital you treat any illness early to stop them from progressing to something untreatable.

How To Treat Dropsy

If you think you can bring your betta back from the brink then the most common treatments are frequent water changes as well as administering an antibiotic (if you think it’s root cause is a bacterial infection). You can also try methylene blue dips however, chances of success with either is slim.

To learn more about dropsy then check out this article. If you haven’t read up on dropsy already then you definitely NEED to read the article. After all, you could save your bettas life.

4. Malawi Bloat

It’s incredibly rare that your betta is suffering from Malawi Bloat, in fact, it’s probably the least likely sickness that your betta is suffering from. However, on occasion, it is known to happen. And unfortunately, once you notice the signs of Malawi Bloat, it’s normally too late to save your betta.

Symptoms of Malawi Bloat

Aside from the obvious bloating symptom, there are other symptoms that you may notice when your betta is suffering.

Trouble Breathing

You may notice that your betta is struggling to breathe, and spending lots of time at the top of the tank to get to air easier. However, if you notice this, then it may not be Malawi Bloat, but it could be being caused by something equally serious, such as not enough oxygen in the water, ammonia poisoning or temperature shock.

(There are so many reasons your betta could be gasping for air, and it’s good to know them all!)

 Lack Of Appetite

Again, it’s another symptom that can be related to many illnesses, but in rare circumstances, it could also be due to Malawi Bloat.

(Here are all the reasons your betta may have stopped eating, and what you can do about it!.)

Causes of Malawi Bloat

The general consensus is that Malawi Bloat is either caused by a parasite or bacteria in your tanks water. However, no ones sure which one it is. The best way to reduce the chances of Malawi Bloat is making sure you keep the water conditions in your tank great, as well as feeding your betta food from reputable sources.

How To Treat Malawi Bloat

If you think your betta is suffering from Malawi Bloat, then in the vast majority of cases it’s going to be fatal. However, if you do want to treat it then you’d need to take your betta to a vet or specialist.

5. Tumor

In other rare circumstances, a bloated belly in your betta fish can be caused by a tumor. While it is rare that your betta will have a tumor that causes a bloated stomach, when it does happen, unfortunately, there’s nothing left that you can do, and the only option is euthanasia.

Fortunately, tumors aren’t common in bettas, so you shouldn’t worry too much about this! And if you’re worried that you’ve done something to cause the tumor don’t worry. There’s nothing you can do to stop a tumor; if it’s going to happen, it’s going to happen.

6. Producing Eggs

If bloating is occurring in one of your female bettas then she may be producing eggs. Fortunately, there are other signs apart from swelling that will let you know your girl is full of eggs.

The signs you can expect to see on top of bloating include white vertical stripes running across her body as well as a white spot or tube on her stomach where the eggs are going to come from.

(Still not sure what are your bettas suffering from? This article lists the diseases and illnesses that can be an affliction to them! It’s well worth a read to help you figure it out!

What To Do If You Notice Your Betta Fish Is Bloated

When you notice your betta fish is bloated, you should act quickly to sort the problem out and keep him healthy. Here are the steps you should take.

1. Diagnose The Symptoms

The first step is to try and diagnose exactly what’s wrong with your betta. If you think it’s constipation then he can be kept in his main tank.

2. Move Him To A Quarantine Tank

If it’s not constipation, or you’re not sure, and your betta is living in a community tank, then you should move him to a quarantine tank. This will stop him from potentially making other fish ill, and it will also make treating him easier. If he’s suffering from swim bladder disease, due to injury, it will also make it easier for him to rest.

(Find out how to setup a quarantine tank for your betta in a handy step by step guide!)

3. Begin Treatment

Once you’ve got your betta into a quarantine tank, you can begin whatever treatment you think is going to help. Just remember, you should keep your betta in a quarantine tank even after he looks better, just to make sure that he’s fully recovered.

4. Monitor The Symptoms

If possible you should check your betta every few hours to monitor his symptoms and make sure things aren’t getting worse.

How To Prevent Bloat In Your Betta Fish

It’s always better to prevent a betta fish being bloated rather than treating it. Luckily, the key to preventing bloat and any disease are pretty similar and pretty simple!

1. Keep The Water Clean

Keeping the water clean is one of the best things you can do to reduce illness in your betta. Performing water changes every week or couple of weeks (depending on the size of your tank) is going to remove any build up of ammonia and waste in the tank. It’s also going to remove a lot of bacteria and parasites from the tank that could do your betta harm.

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2. Use High-Quality Food

You should also make sure you’re using high-quality food and make sure your betta is getting a balanced diet. While you can feed him nutritional betta pellets, they shouldn’t be his only source of food. Freeze dried, dried, frozen and live food should also be used.

Daphnia is best for bettas, however, you can also use mosquito larvae and brine shrimp. You may have heard that bloodworms should be a staple in a bettas diets, however, they should only be used as a treat. (Find out why.)

Fluval Bug Bites Tropical Fish Food, Small Granules for Small to Medium Sized Fish, 1.6 oz., A6577
  • Tropical fish food that contains up to 40%, nutrient-rich Black Soldier Fly Larvae, the first ingredient

3. Avoid Aggressive Tank Mates & Sharp Objects

Aggressive tankmates and sharp objects in your tank can often cause damage to your betta. Even if the damage isn’t direct to his stomach the stress or infection can often cause his organs to be put under stress resulting in different ailments. Luckily there are plenty of tank mates and decorations to choose from that aren’t going to harm your betta!

(Here are 30 of the best tank mates you can add to your bettas tank as well as how to make the arrangement work!)

4. Use An Adequately Sized Tank

You may have heard that 2.5 gallons is big enough for bettas. However, if you want your betta to be happy then you should never go smaller than 5 gallons. At 5 gallons your betta will have enough space to swim around happily. It also reduces the chance of water fluctuations that can stress your betta and in extreme cases, kill him.

(Find out why the 5 gallons is the ideal minimum tank size for betta fish.)

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Is my Betta Fish Pregnant or Bloated?

It can sometimes be difficult to determine if your Betta fish is pregnant or just bloated. Keep an eye out for a few key indicators such as a larger belly, white stripes, and a dark spot near the anal fin.

How Long Does it Take for a Betta to Recover From Swim Bladder Disease?

If your Betta is suffering from swim bladder disease, it can take anywhere from a day to three days to see improvement. So, make sure to monitor your Betta closely during this time.


A bloated betta fish is fairly common, and luckily in most cases, the causes are easily treatable. Here are the main points to remember from this article to make sure your betta is going to stay happy and healthy.

Taking care of your Betta can be challenging, but it’s not impossible. Click here to read an article with everything you need to know about Betta fish care.

  • There are lots of causes of bloat, while some of them are deadly, in most cases, they’re rarer.
  • Constipation is one of the leading causes of bloat. It can be caused by a poor diet and inactivity
  • As well as bloating your betta may not be able to pass stool and he’ll also lose his appetite.
  • To treat constipation, fast your betta and then feed him daphnia after a couple of days.
  • Swim bladder disease could also cause bloating. Damage, constipation and water fluctuations can all cause swim bladder disease to occur.
  • The symptoms of swim bladder disease may also include trouble swimming, lack of appetite, a curved back and lethargy.
  • There are different treatments for swim bladder disease depending on what’s causing it.
  • Bloating in bettas can also be a sign of dropsy which is often fatal. The main symptoms associated with dropsy as well as bloating is pinecone scales and a curved spine.
  • Poor water quality, disease, poor diet, and internal damage can all cause dropsy.
  • Treating dropsy is extremely difficult, as by the time the symptoms are noticeable the damage is often too far gone.
  • In rare cases, it could be Malawi Bloat or a tumor. In both cases, there’s not much you can do to save your betta.
  • If your female is suffering from bloating then she may be full of eggs.
  • To prevent bloating in your betta keep the water quality good, feed him a varied and nutritional diet, avoid aggressive tank mates, sharp objects, and use an adequately sized tank.


About the author

Hey! I'm Antonio!

Betta fish keeper for over 6 years now! Since owning a betta I've also housed all kinds of tropical fish, and have seen all manner of problems and how to look after them!

If you need any advice you can always message me or better yet join the Facebook group where a community can answer your questions!

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