bloated betta fish

Why Is My Betta Fish Bloated? Causes, Symptoms, and Prevention

A bloated betta fish can bring anxiety for a first-time owner or any fishkeeper for that matter. While bettas have a reputation for hardiness and an ability to survive in poor conditions much longer than other fish species, this doesn’t mean they’re above illness. 

Bloat is one of the most common illnesses for betta fish, and it can be scary to see your betta with an inflated tummy.

Not to worry, though. Betta fish bloat is mostly curable. 

🐠 If you want to be 100% certain you’re giving your betta its best life, try our interactive course with exclusive, in-depth video tutorials you won’t find anywhere else.

Products We Trust


Water conditioner to be used with every water change to kill bacteria in tap water

$11.31 ($13.46 / Ounce)

Fish flakes for betta fish


Can be used as a laxative for fish

$19.17 ($0.24 / Ounce)

Epsom baths can help with constipation

04/24/2024 07:22 pm GMT
bloated betta fish

What Does a Bloated Betta Fish Look Like?

A bloated betta fish has an enlarged, protruding belly. This condition can affect both sides of your betta or just one, causing him to appear lopsided. 

Bloat will often cause betta fish to have trouble swimming, causing them to get stuck at the surface or bottom of the tank. And getting stuck at the bottom of the tank can be lethal for your betta, as he’ll be unable to get to the surface to breathe.

What Are the Symptoms of Betta Fish Bloat?

The best indicator of bloat in betta fish is a swollen, protruding belly. It may affect one or both sides of the fish, causing him to swim sideways or lopsidedly. Here are some characteristic symptoms of bloat that you can look out for:

  • Stomach swelling on one or both sides of the fish
  • Inability to defecate
  • Getting stuck at the top or bottom of the tank
  • Looking fatigued or unconscious
  • No interest in food

What Are the Causes of Betta Fish Bloat?

Betta fish bloat is caused by several conditions. These conditions have characteristic symptoms that can help you pinpoint the exact problem. Here, we’ve outlined the causes of betta fish bloat, their symptoms, and treatments 

Betta fish suffering from constipation have a much higher chance of survival than those with dropsy. When dealing with a constipated betta, you might notice the following symptoms:


Constipation is the most common cause of bloating in betta fish. The condition is not fatal in itself, however, constipation can be a tell-tale sign of fatal diseases in betta fish.

Symptoms of Constipation in Betta Fish

Inability to Pass Stool

If you don’t regularly check on your betta fish, this symptom will be hard to notice. This is, however, the clearest sign of constipation. Knowing this, you’ll want to check for droppings in your pet’s aquarium. 

Fish dropping is often long, stringy, and black or brown in color, but can resemble the color of your fish’s feed. Depending on how often you feed your betta and the water’s temperature, you should be able to spot a few strings of feces a day.

Given their simple gastrointestinal tract, a betta should poop at least once a day. Watch out for accumulated feces, as they can be easily mistaken for fresh fish poop. Gravel vacuum the bottom of your betta’s aquarium to get rid of any accumulated feces before you begin checking.

Loss of Appetite

A good appetite is a sign of a healthy betta fish, so you’ll notice if your betta isn’t eating quite easily. Bettas are rarely ever full, but constipation can be one reason they aren’t eating.

Causes of Constipation in Betta Fish

Inadequate Exercise

If you keep your betta in a small tank, he’s likely not getting enough exercise. Lack of exercise can contribute to a constipated betta fish. 

Poor Diet

Overfeeding your betta fish can cause him to become constipated. Betta fish have receptors in their stomachs that signal to their brains when they’re full. But, your betta may continue to eat even after he’s full.

What’s worse, overfeeding your betta fish can introduce life-threatening toxins into his water. 

A diet of low-quality feed can also result in constipation. If you feed your betta only fish flakes and freeze-dried food, he may become constipated.

Lastly, the low water temperature can be responsible for betta fish constipation. Low temperature slows the digestive process in fish, resulting in a constipated betta.

We earn a commission if you make a purchase, at no additional cost to you.
04/24/2024 11:09 pm GMT

How to Treat Constipation in Betta Fish

A constipated betta fish is often easy to treat. Fasting your betta for two to three days should help empty his bowels and get them moving again. After this fasting period, you can feed your betta live food like mosquito larvae, bloodworms, and scallops.

To loosen your betta’s bowels, feed him daphnia, which acts as a laxative for fish. If your betta is not a fan of daphnia, try feeding him peas, prepared as follows:

Take a pea, and boil it as you would for yourself. Then, peel it completely and cut it into quarters. Cut one of the quarters into bite-sized portions and feed them to your betta. Peas aid constipation because they are rich in fiber. Be careful to avoid feeding your betta any pea skins, as they’re hard to digest, and you might worsen the situation.

If there isn’t any progress after three days, you should consider giving your betta an Epsom bath.

We earn a commission if you make a purchase, at no additional cost to you.
We earn a commission if you make a purchase, at no additional cost to you.
04/24/2024 11:30 am GMT

Swim Bladder Disease

The swim bladder is an organ that helps your betta fish to maneuver the water and keep afloat.

Swim bladder disease is the second most common cause of bloat in betta fish. The disease isn’t an illness, but is a name coined for diseases that affect a fish’s swim bladder, affecting its buoyancy. 

Coincidentally, swim bladder disease can result from constipation and constipation can result from swim bladder disease. So, its symptoms are somewhat tricky to identify. When constipation causes swim bladder disease in betta fish, however, it’s usually from overfeeding and high nitrate levels in the water.

Symptoms of Swim Bladder Disease

Several symptoms characterize swim bladder disease in betta fish. Luckily, they’re easy to spot.

Difficulty Swimming

The most obvious sign of swim bladder disease is buoyancy issues. A fish with swim bladder disease will:

  • Stay stuck at the top of the water
  • Sink to the bottom of its aquarium
  • Swim side to side or lopsidedly
  • Have difficulty staying in one position
Loss of Appetite

A betta fish suffering from swim bladder disease will also have trouble eating. The loss of appetite results from severe buoyancy issues and an inability to reach the water’s surface.


Lethargy is a condition characterized by drowsiness, extreme fatigue, and prolonged sleep patterns. Swim bladder disease can cause your betta fish to become lethargic and he may mimic a dead fish. The lack of oxygen from poor buoyancy can even result in a lack of consciousness.

Curved Back

When a betta fish suffers from swim bladder disease, the abdomen inflates and pushes other organs aside. The condition can sometimes cause the fish’s spine to curve outward.

Causes of Swim Bladder Disease

Swim bladder disease occurs for several different reasons, so you must identify the cause correctly before treating. Otherwise, you’ll waste time and maybe even worsen the situation. Here are some possible causes of swim bladder disease:

Compression on the Swim Bladder

Compression of the swim bladder is the most common cause of swim bladder disease. It occurs when a fish eats too quickly and swallows a lot of air, causing your betta’s stomach to enlarge and push into his swim bladder.


Constipation is a common cause of swim bladder disease. As mentioned earlier, constipation can cause swim bladder disease, and swim bladder disease can cause constipation. 

A constipated betta fish will have a hard time swimming and keeping afloat. If you notice a bloated, not-so-buoyant betta, he probably suffers from constipation.


If you keep multiple betta fishes in the same tank, they’ll occasionally get aggressive and hurt themselves. Depending on the degree, fish-on-fish aggression can lead to swim bladder disease. It can also occur if your betta injures himself on a tank ornament or jumps out and harms himself during the landing. 

Parasites and Bacterial Infection

Widely unknown, swim bladder disease can occur when your betta’s swim bladder is infected. Bacteria can enter your betta’s body through wounds and gills. Once aside, they inflame and infect the swim bladder.

If your betta’s swim bladder is infected, you may notice that his feces are a different color or consistency than normal.


When fish are transported long distances or inappropriately, the change in their environment or water’s temperature and pressure can expand and rupture their swim bladder. Depending on the severity, this situation can be lethal.

Water Quality

When the water quality is poor, your betta can become lethargic and struggle to keep afloat. In an attempt to remedy this, his swim bladder may inflame and enlarge. 

Factors like high levels of ammonia and nitrates contribute to poor water quality and increase the chances of swim bladder disease in your betta. For this reason, always keep your betta’s water clean.

How To Treat Swim Bladder Disease

In many cases, fasting your betta is the most effective treatment for swim bladder disease, especially if caused by overeating or eating too fast.

Here are some treatments for swim bladder disease:

Removing Excess Air

If your betta fish is experiencing positive buoyancy, removing the excess air is the next best solution. To do this, fast your betta for two to three days. This is enough time for him to expel the excess gas.

Maintaining the Water Quality

The water quality in your betta’s tank can either help him thrive or cause illness. So, maintaining water quality is crucial to your betta’s well-being. A partial water replacement is a great way to clean out disease-causing impurities from the tank.


Dropsy refers to a condition in fish caused by fluid buildup inside the fish’s body or tissues. Unfortunately, the chances of survival from dropsy are very slim. While some fish will recover from dropsy, most times, you’ll need to consider euthanasia.

Symptoms of Dropsy

There’s one symptom that particularly characterizes dropsy in betta fish:

Pinecone Scales

A betta fish suffering from dropsy may exhibit pinecone scales. Pinecone scales indicate that the scales on your betta’s body no longer lie flat. Instead, they stick out of the skin and make the fish look like a pinecone.

At this stage, the betta’s chances of survival are very low, as pinecone scales signal a severe infection. 

Essentially, the fish’s organs are so damaged that they begin to swell, forcing his body to bloat and pushing his scales out. By now, the organs are already too damaged for life after survival.

Causes of Dropsy

Like swim bladder disease, several factors can cause dropsy. They, however, all share one attribute: they stress the betta fish. Here are the causes of dropsy:

  • Poor water quality and diet
  • Internal injury
  • Illness and disease

Malawi Bloat

Malawi bloat is a fish disease commonly characterized by abdominal swelling. It isn’t necessarily a disease but a symptom of an underlying condition.

Symptoms of Malawi Bloat

  • Trouble breathing
  • Lack of appetite

Causes of Malawi Bloat

Malawi bloat is either caused by a parasite or bacteria in your betta’s water, although the causes are still a bit elusive. 

The most effective way to reduce Malawi bloat is to ensure the quality of your betta’s water and feed him from a reputable source.  

Is my Betta Fish Pregnant or Bloated?

Pregnant fish often look like bloated fish. Check for the main signs of pregnancy in betta. Look for an enlarged belly, white vertical stripes, and a dark spot near the anal fin.

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

Betta can recover from swim bladder disorder in at little as a day. But, it can take up to three days to see improvement.

The Key Takeaways

More often than not, a bloated betta is no cause for panic. But, you must know how to spot your betta’s symptoms before you can treat him.

Have you found this article helpful? Let me know what you think in the comments, and share this article to help another fish enthusiast!

If you’re new to fishkeeping and want to give your betta the best care possible, this is the only betta fish care guide you’ll need.

Similar Posts