Why Is My Betta Fish Swimming Sideways? Listen To A Vet!

So, you are a happy betta fish owner who takes great care of your betta fish, but one day you come home from work and almost walk past your betta but you stop dead in your tracks.

“Did I really just see that?”, you ask yourself.

“Was my betta fish really swimming sideways?”

Sadly as you observe your betta fish, it is indeed swimming sideways.

Aquarium betta fish were bred for long fins and bright colors. Unfortunately, the long fins make betta fish poor swimmers. If you have low current in your aquarium, your aquarium water is clean and your betta isn’t a weirdo who likes to swim sideways, then your betta fish probably has what is called ‘Swim Bladder Disease’.

However, never fear because it is not actually a disease, and usually goes away on its own.

Let’s dive in(no pun intended) and take a closer look…

What Is Swim Bladder Disease In Betta Fish?

All betta fish are bony and have an organ named a ‘swim bladder. The swim bladder holds oxygen so the betta fish can stay buoyant, which really means to be able to float or maintain a desired position in the water.

Betta fish are able to breathe in oxygen at the water’s surface. The oxygen quickly gets filtered into the swim bladder.

Swim bladder disease isn’t really a disease but is caused when something is wrong with your beta fish’s swim bladder.

What Causes Swim Bladder Disease In Betta Fish?


It is usually caused by overfeeding, especially in baby betta fish. Baby betta fish are so small that it is easy to overfeed them. People usually overfeed their baby betta fish with baby brine shrimp.

Hmmm… I wonder if the baby brine shrimp sometimes have swim bladder disease as they are swimming sideways into the mouth of the betta fish hahaha. Okay, I’m an aquarium expert, not a comedian so let’s stay focused here…

Adult betta fish can sometimes overeat as well, especially if it is part of their personality.

Poor Water Quality

Although overeating is usually the cause, water quality is often overlooked as the cause of swim bladder disease.

Many contributing factors can cause swim bladder disorders. One of the most overlooked components is water quality. Poor water quality can result in sudden and chronic stress in fish. Stress causes disruption in regular homeostasis, which can result in negative or positive buoyancy disorders. If your fish presents with a buoyancy disorder, water quality should be checked immediately and corrected if necessary.

If your fish needs to be seen by a doctor, make sure your veterinarian is comfortable working on aquatic animals before you proceed.

The best way for your veterinarian to evaluate the swim bladder is by taking an X-ray. X-rays can show the positioning and size of the swim bladder very clearly. It can also show if there is any fluid in the swim bladder, which is not a normal condition. Swim bladders can become displaced due to disease processes, which will be easily seen on X-rays.


Part of poor water quality can also be low water temperature. A betta fish’s water needs to be between 75-80°F.

If the temperature of your betta’s water drops below 75 then it can slow the metabolism, of your betta fish. This causes your betta fish to become constipated which can lead to problems with the swim bladder.

Still, on poor water quality, swim bladder disease can actually be a side effect of your betta fish having a bacterial infection. I say poor water quality because that is how a betta fish usually gets a bacterial infection.


Stress is also usually a side effect of poor water quality or sickness.

Stress can also come from a temperature change in the water, too much light in the tank, or a new tankmate.

Female Bettas can get swim bladder disease from injuries during courtship and breeding.

Symptoms of Swim Bladder Disease

  • Your betta fish is swimming erratically, not just sideways, but the main symptom is swimming sideways.
  • The most indicative symtom after swimming sideways is appetite loss.
  • If the betta fish’s swimbladder is to big, they will float to the top of the tank and maybe even float sideways.
  • If the swim bladder of your betta is too small, they will sink to the bottom of the tank and remain there.
  • No matter how hard your betta tries to stay in a certain position, they will keep sinking or floating since they lose their buoyancy. You will notice them struggling.
  • The betta fish’s back may seem curved or their belly may seem bloated.
  • Your betta fish seems lazy, they arent moving around as much as usual and may seem to be sleeping.
  • The betta fish’s fins may seem clamped to their body which is a sign of bacteria or parasites causing swim bladder disease as a side effect.
  • If the betta keeps shiking its body, the swim bladder disease could be a side effect from parasites or bacteria.

How To Treat Swim Bladder Disease In Your Betta Fish

First, you will need to make sure your betta fish has swim bladder disease from overeating. To do this, you will need to rule out other causes first.

If you are an experienced fishkeeper then you already know your water is chlorine-free, filtered properly, and at the proper temperature.

If you are inexperienced then you need to check your water parameters immediately and check the water temperature.

If your water parameters are good then make sure your betta doesn’t have any physical signs of sickness that may be causing swim bladder disease as a side effect.

If you have good water quality, temperature, and lighting, then it is better to quarantine your betta to get rid of the swim bladder disease.

If you quarantine, your betta, you can starve them for up to 72 hours.

If your betta still has swim bladder disease then it is better to consult a veterinarian because swim bladder is usually not from a parasite or bacterial infection.

If your betta fish does go back to normal after starving then you should try some different foods and add more variety to their diet.

Listen To A Real Vet! Not The Average Joe’s on Google!

Here is a home treatment from petmd.com – a vet written and vet reviewed pet blog:

Depending on the cause, swim bladder disorders may be temporary or permanent. If your fish has a permanent swim bladder disorder, they can still live a full and happy life with some lifestyle modifications. With positively buoyant fish, some of the fish’s body can spend too much time above the water’s surface, making it important to keep their skin moist. Do not cover the top of your tank to keep your fish submerged. This will result in decreased oxygen diffusion. Ask your veterinarian what can be applied to fish skin to protect it from air. Negative buoyancy disorders, with a fish spending too much time close to the bottom of the aquarium or pond on its side, belly, or head, will need to be controlled with a clean, non-abrasive substrate, such as glass stones. It is critical that these tanks be kept very clean.

Fish with compromised swimming ability will need help eating. With any buoyancy disorder, you will need to introduce hand-feeding. Be patient and try some tasty treats, such as small bits of shrimp, to get them started. Once they have gotten the idea, go back to their regular diet. Fish are smart and will catch on to the new routine quickly. When hand feeding, do not grab your fish! Bring the food to them in whatever position works best for them.


Swim Bladder Disease Prevention

Here is what petmd.com says about Swim Bladder Disease Prevention:

Buoyancy disorders in fish can be difficult to decipher and may have no permanent solution. If you have a fish that is starting to have problems swimming, check your water quality first. Water quality is often overlooked with swim bladder disorders. With physostomous fish, try a sinking or neutrally buoyant diet to keep excess air from getting into the swim bladder.

If the swimming problem persists, consult your local aquatic veterinarian to help set up X-rays to evaluate the swim bladder. Once the problem has been diagnosed and discussed, make a plan with your veterinarian for your fish’s future. Fish can live long, happy lives with swim bladder disorders, it will just require a few changes to your tank and regimen.


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