Why is My Goldfish Swimming Sideways? Every Thing About Swim Bladder Disease

Almost every one of us has seen goldfish swimming sideways. But this is not good a thing. They swim sideways because they have a disease or sometimes for stress.

If you do not treat it right away your pet goldfish may die. So, why is my goldfish swimming sideways? In this article, I will tell you the reasons why goldfish swim sideways and some treatments.

Let’s begin,

Why is My Goldfish Swimming Sideways?

Many potential reasons why a fish might start swimming sideways in an aquarium. While the cause can sometimes be difficult to determine, some of the more common reasons include:

  • Poor water quality
  • Physical injury or illness
  • Parasites or other infections
  • Stress

If you notice your fish swimming sideways for no apparent reason, take a close look at the quality of your aquarium water.

Ammonia, nitrites, and nitrates can all cause stress and disease in fish, leading to abnormal swimming patterns. If your water tests reveal high levels of these toxins, take steps to correct the problem immediately.

Why is My Goldfish Swimming Sideways?

In some cases, fish may start swimming sideways due to physical injuries or illnesses. If you notice your fish rubbing against objects in the aquarium or scratching itself excessively, it may be trying to relieve itchiness caused by parasites or infections. If your fish’s body looks swollen or bloated, it could be suffering from a more serious condition like dropsy.

In many cases, stress is the underlying cause of sideways swimming in fish, and fish may become stressed due to poor water quality, overcrowding, or aggression from tank mates.

If you notice your fish swimming erratically or hiding more than usual, take steps to reduce the stressors in its environment.

This may involve performing more frequent water changes, adding additional hiding places to the aquarium, or rethinking your tank mates.

Improper Feeding

One of the most common reasons for sideways swimming in goldfish is improper feeding. When they are fed too much or too often, goldfish can become overweight, and swimming can become difficult.

Goldfish are also very messy eaters and often produce a lot of waste. If there is too much waste in the water, it can cause stress and disease.

To avoid overfeeding your goldfish, only give them as much food as they can eat in one sitting. Once the food is gone, remove any remaining waste from the tank.

It’s also a good idea to fast your fish one day per week to allow their digestive system a chance to rest.

Bacterial Infection

Bacterial infections are a common problem in fish and can cause various symptoms, including sideways swimming.

Bacteria can enter the aquarium through contaminated water, food, or equipment and quickly spread to other fish in the tank.

The most common symptom of bacterial infection is lethargy. Fish may stop swimming and lie at the bottom of the tank, often hiding among the plants or decorations.

In some cases, fish may also exhibit symptoms like loss of appetite, cloudy eyes, and fraying fins.

If you think your fish may have a bacterial infection, it’s important to take action immediately. Begin by water changing and vacuuming the gravel to remove any waste and debris.

Next, treat the water with a quality aquarium disinfectant. Be sure to follow the instructions carefully to avoid harming your fish.

Water Temperature Change

Water temperature is another common reason for fish to swim erratically. A sudden change in water temperature can cause stress and make it difficult for the fish to swim properly. If the water temperature is too high or too low, the fish may become sick or die.

To avoid stressing your fish, try to keep the water temperature consistent. If you need to change, do it gradually for several days, giving the fish time to adjust and minimize the risk of stress or illness.

What is a Swim Bladder disease?

A swim bladder disease is a problem that can affect goldfish and other fish. The swim bladder is a sac-like organ that helps the fish control its buoyancy in the water.

When the swim bladder is inflamed or infected, it can cause the fish to swim erratically and even sink to the bottom of the tank.

Several things can cause a swim bladder disease, including infection, and constipation. In some cases, the exact cause may be unknown.

Treatment for a swim bladder disease will depend on the underlying cause. For example, if the fish is constipated, you may need to feed it a special diet or give it a mild laxative.

If the fish has an infection, you may need to treat it with antibiotics. In some cases, surgery may be necessary to correct the problem.

Diagnosing and Treating Swim Bladder Disease

The best way to diagnose the swim bladder disease is by a veteran doctor. Bring your pet fish to a veteran doctor to check if they have swim bladder disease or any other disease.

Here is a list of symptoms of swim bladder disease:

  • Swimming sideways.
  • Floating to the top of the tank.
  • Struggling to stay upright, turning on its side, or upside down.
  • Curved Back

You can also check their behavior to determine if they have any disease, but it is hard to determine their disease by only looking at their behavior.

Here is some treat you can do:

  • Let the fish fast for three days.
  • Fix the water temperature, and maintain the stable water temperature in your aquarium.
  • After completing the fast, feed them boiled or skinned peas. Ensure that the pea is spices-free, boil the peas with only water.


Swim bladder disease is not the only problem that can cause a goldfish to swim erratically and Constipation but also make a goldfish swim sideways or upside down.

Goldfish need a lot of fiber in their diet to keep their digestive systems functioning properly. If they don’t get enough fiber, they may become constipated. Constipation can cause goldfish pain and discomfort and lead to swim bladder disease.


Suppose your goldfish is suffering from constipation. Constipation is a few things to help. One common treatment is to give the fish some Epsom salt and add one teaspoon of salt per gallon of water and mix it well.

When treating a fish, quarantine that fish and treat it separately from other fish.

Hey, I am Shuvradeb Biswas a content writer. Fishkeeping is my hobby. There are many problems I faced during my first fishkeeping. So, I made the KeepingWorld.com blog to help new fishkeepers.

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