Is your betta fish swimming vertically with the tail up? That’s abnormal and a possible sign of vertical death hang. If the behavior lasts for extended periods, I recommend calling a vet to examine your fish and offer medical solutions.

Below, I’ve explained possible reasons for betta fish swimming with the head down and tail up and what you should do. First, what’s the problem?

Vertical death hang is when a betta fish floats vertically in the tank. Floating with the head down and tail up and struggling to stay upright is caused by swim bladder disease which can result from illness, physical injury, or environmental causes.

Betta fish head down tail up

Causes and fixes for vertical death hang

Quite a number of factors can cause the head-down-tail-up position in bettas. The stance mostly points to your fish struggling to maintain its normal swimming posture.

Here are the causes of vertical death hang in bettas:

Swim bladder diseaseTake your fish to an aquatic veterinarian.
Constipation (bloating)Fast the fish, then give high-fiber foods.
Physical traumaNurse the fish till recovery. See a vet.
Ammonia poisoningChange 25-50% of water to detoxify.
Small tankHouse your better in at least 5 gallons.

1. Swim bladder disease

A swim bladder is a vital organ that dictates the way the body of your fish is positioned as it swims or rests. By expanding and contracting naturally, the organ helps fish stay balanced and buoyant in the tank’s water. 

Any disease or infection that attacks the swim bladder affects the ability of the betta fish to control how it swims and achieve balance. This factor can also affect other species, like guppies making them swim with heads up and tails down.

Apart from the head facing downwards, other signs of a swim bladder disease are swelling around the belly, lethargy, and a curved spine. 

Swim bladder issues can result from poor water conditions, physical injury, infections, birth defects, and constipation.

2. Constipation

Poor diet, overeating, and lack of exercise are bettas’ main causes of constipation. Overeating causes various health issues, especially constipation, and obesity.

A constipated betta will have swollen intestines that can pressure the swim bladder, making it lose its natural shape. The result is loss of balance, so your fish may float with the head down and tail up.


Fast your betta fish for 1-2 days until constipation clears. Alternatively, feed the fish a chitin-rich diet such as daphnia to help with bowel movements. Meals with high fiber content, like peas and brine shrimp, treat constipation and bloating.

Offer only the recommended food portions so that there is no overfeeding.

The death hang posture should resolve on its own as constipation resolves. Sooner or later, the seemingly dead betta will come back to life. If not, see a vet for further advice.

If you are offering pellets, soak them first for a few minutes. Soaking the pellets make them safe for digestion and discourages the swelling of the stomach.

3. A small tank 

A smaller tank stresses and triggers abnormal behaviors in betta fish, including having the head facing the tank’s bottom in certain instances.

The fish’s head down and tail up may be a way to find a way out of the small tank or tell you it needs a bigger space for more leisurely swimming and movement.

Best fix

Provide at least a 5-gallon tank for your bettas to have enough space to swim normally.

Dr. Krista Keller, a veterinarian at the University of Illinois Veterinary Teaching Hospital advises that bettas “should not live in bowls. Instead, they should ideally be in a 5-gallon glass or plastic tank or larger.” (Source)

4. Shock due to poor water conditions

If the water parameters are not healthy for betta fish, swim bladder issues can occur and trigger death hang. Water pH, temperature, and waste accumulation issues can all lead to the problem. Constant temperature changes can even shock and kill your fish.

Best fix

Fixing the water parameters will solve the erratic swimming posture in your fish. Bettas prefer a water pH level of between 6.5 and 8 and a temperature range of 75-80°F. Monitor and keep only safe levels of ammonia and nitrite.

5. Ammonia poisoning

Lethargy, vertical death hang, and cloudy eyes are possible signs of ammonia toxicity in the aquarium. These can also signify a betta’s behavior before death due to stress, infections, or unfavorable water conditions.

Overstocking often leads to the accumulation of ammonia from decaying organic matter from feces and leftover foodstuff in the tank. As ammonia builds up, oxygen levels reduce sharply leading to suffocation.

An unusual vertical floating position in bettas is likely a sign of poor water conditions in the tank.

Best solutions

  • Cycle the water frequently.
  • Perform a 25-50% water change immediately.
  • Add ammonia detoxifier into the tank.

Going forward, avoid overfeeding your fish as it only causes increased waste production in the tank. Leftover food is also a problematic source of ammonia as it decays.

6. Parasite infection

Some parasites such as nematodes can attack your fish and cause problems to the swim bladder, leading to the vertical swimming position.

According to Roy P. Yanong, professor and Extension veterinarian, Program in Fisheries and Aquatic Sciences, “adult and other life stages of nematodes can be found in almost any part of the fish, including the coelomic (body) cavity, internal organs, the swim bladder…” (Source).


If you suspect parasite infestation as the cause of the betta death hang symptom, take your betta to a veterinarian for proper diagnosis and treatment. I would advise against treating the fish yourself as that may require surgical removal of parasites such as tapeworm.

7. Physical trauma

Betta fish are very aggressive fish and will fight other fish in the aquarium. I’ve had instances of bettas constantly glass-surfing and injuring themselves. They even fight their own reflections.

Such aggression is the main cause of physical trauma, leaving the bettas injured. Torn fins, injured swim bladder, and other bodily damages can be the reason for the vertical death hang in bettas.

Best fix

Take your betta fish to a vet near you for treatment. There have been cases of successful surgical pressure relief of the swim bladder published in the American Journal of Veterinary Medicine as explained by Greg Lewbert here, so, your fish can be saved.

Does the swim bladder go away?

The swim bladder disorder can go away or remain permanently depending on the cause. Earlier spotting of swim bladder problems gives you enough time for treating and recovering affected bettas. 

Even if your betta fish has a permanent swim bladder disorder, still, it can live a happy, long life. But, you have to try a few lifestyle changes. For instance, you may need to assist your fish with eating via hand-feeding.

More about bettas:

  • Why won’t my betta fish eat?
  • Why is my betta fish not moving?

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