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Why Is My Betta Fish Bloated? Causes & Remedies

One of the issues I would rather avoid with my betta fish is bloating which unfortunately occurs sometimes.

Quick Answer

If your betta fish is bloated, there may be a variety of underlying issues, such as overfeeding, constipation, internal parasites, dropsy, tumors, poor water quality, and more. Each of these issues can cause bloating and betta fish, and they must be addressed separately to remedy the situation.

Keep reading to find out exactly what to look for to identify bloating in your betta fish. We’ll also talk about how to determine what the cause of the bloating is, and then what the appropriate solution is.

Signs of Bloat in Betta Fish

There are various physical signs and behaviors in betta fish to look out for as indications that they are bloated. The following are the most common ones.

Healthy betta

General Swelling

If you see that the abdomen of your betta fish is visibly swollen, appears round, and distended, it may be that your betta fish is bloated. If your betta fish looks like it just ate a massive meal, even though it didn’t, it’s probably bloated.


If you notice that your betta fish is not only looking a bit chunky, but also much less active and spends a lot of time resting near the surface of the water or at the bottom of the tank, bloat may be to blame.

Loss of Appetite

Yet another very clear indication that your betta fish is suffering from bloating, especially if you also notice that it’s looking really swollen, is a loss of appetite. A bloated betta fish likely doesn’t feel very well, which means that it’s also not going to eat.

Waste Issues

If your betta fish is bloated, there may very well also be some waste issues. By this, I mean that your betta fish could be constipated, or you might notice that the feces is somewhat abnormal, such as discolored or stringy. 

Sometimes, your betta fish may not pass any waste whatsoever for several days on end.

Swimming Difficulty

Another clear sign that your betta fish is suffering from bloat, especially if it is also swollen, is a pronounced difficulty swimming. Bloat may cause added weight or balance issues to occur, which can cause a betta fish to struggle when swimming.

Changes in Behavior

If your betta fish is bloated, you may also notice some behavioral changes. Your betta fish may be more agitated or aggressive, as it tries to deal with its increased discomfort.

Raised Scales

In very severe cases, especially if your fish is suffering from something like dropsy, which is generally characterized by very severe bloating, the scales may also become raised. As I will discuss it directly below, there are various causes of bloating in betta  fish, and dropsy is one of them.

Causes and Remedies of Bloating in Betta Fish

There are no less than six different causes of bloating in betta fish, so let’s take a quick look at each of them to figure out what is going on with your poor little fish.


One of the most common causes of bloating in fish is overfeeding. If you feed your betta fish far too much food, more than it can consume in about two or three minutes, twice per day, then you are likely overfeeding your fish.

Remember, betta fish are very small and don’t need much food. Furthermore, if you are giving your betta fish too much protein, this can also lead to such issues.

Therefore, you should always feed your betta fish very high-quality food up to twice per day, and no more than it can be eaten in two or three minutes. Make sure to not only follow a regular feeding schedule but also to give it appropriate food.


Although constipation may be caused by overfeeding, it’s more likely that it is constipated if you constantly feed it dried foods.

Dried foods are fine every now and again, but they often don’t contain enough moisture. If you think that this might be the cause, providing your betta fish with a wider variety of foods, especially live or frozen foods, such as brine shrimp or daphnia, may be beneficial.

These foods also often contain natural laxatives, which can assist with this issue. If you plan on continuously giving your betta fish dry food, you may want to soak them first just to moisten them.


There are also several internal parasites, such as worms, which can infect a betta fish and lead to health issues such as bloating.

If you think internal parasites may be to blame, the only real solution is purchasing the appropriate medications designed to kill sad parasites. This means that in all likelihood, you will need to visit a veterinarian.


In very rare cases, betta fish may also develop various tumors or growths internally which may lead to bloating. 

In some cases, the tumors or growth themselves may simply appear to be bloating. If you think that this may be the cause, you’ll need to consult a veterinarian that is experienced with betta  fish.

A veterinarian may be able to surgically remove a growth depending on the location, although it is likely that removal will not be an option. 

In the worst-case scenario, it may be that your betta fish has developed a malignant tumor, such as cancer, in which case there is unfortunately no solution.


Dropsy is an infection that can take place in betta fish as well as many other types of aquarium fish. This is an infection often characterized by raised scales, lethargy, and extreme bloating. 

It is generally a result of bacterial infections. Remember that bacteria are everywhere, and not all fish will develop infections due to them.

The issue often arises when the fish are stressed out and suffer from a weakened immune system. Fish cannot be stressed out due to a wide variety of issues. 

Poor water conditions, tank mates that are bullies, poor feeding practices, and a tank that is far too small are all things that can cause stress in betta fish, among others. A stressed out fish is automatically more susceptible to infections.

The unfortunate reality with dropsy is that it is an extremely challenging type of infection to treat, and the prognosis is often very poor. A betta fish suffering from dropsy needs to be isolated from other fish, or else the infection may spread. 

Although cleaning the tank and improving water quality is an option, if your fish has already developed dropsy, then treatment is very difficult. Some antibiotics may help, but the success rates are not great.

Water Quality Issues

It may also be the case that poor water quality is stressing your betta fish out to the point where it is suffering from bloating. Once again, it’s not as much the water quality itself that is causing the bloating, but rather the increased susceptibility to various types of disease due to higher levels of stress.

Therefore, a simple solution here is to try and maintain very high water quality. To maintain high water quality, using an adequate filtration system that can process at least three times the amount of water in the tank per hour is recommended.

This filtration unit should also engage in all three major types of aquarium water filtration, which include mechanical, biological, and chemical filtration. Also make sure that the tank is properly cycled so that the ammonia and nitrite levels are as close to zero as humanly possible.

Final Thoughts

The bottom line here is that diagnosing the underlying cause of bloating in a betta fish can be extremely difficult. In many cases it can be easily treated, particularly if the cause is poor water quality or feeding issues. 

However, if your betta  fish is suffering from a disease such as dropsy or internal parasites, it is essential to consult a veterinarian as soon as possible.