How to Tell if Your Turtle Is Sick: Signs Every Owner Should Know

As a turtle owner myself, I know how easy it is to miss the early signs that something’s wrong. Turtles don’t cry, bark, or whine — they just change. When my turtle first started acting “off,” I didn’t even realize it was sick until the symptoms became obvious. So I’ve put this guide together to help you catch those red flags early — before it’s too late.

So, how do you know if your turtle is sick? The truth is, turtles show illness through subtle physical and behavioral changes — things like not eating, swelling, weird shell spots, or even just sitting around too much. Let’s walk through the most common signs I’ve learned to watch for, what they mean, and what you can do about them.

Is My Turtle Sick? Here’s How I Could Tell

Not every turtle sneeze or sleepy day is a red alert. But in my experience, when a few of these symptoms show up together, it’s time to pay attention. Here are the top signs I’ve seen in my own turtle — and what they could be warning you about.

1. Loss of Appetite

One of the first things I noticed when my turtle wasn’t feeling right? It stopped eating. And if your turtle suddenly ignores its favorite pellets, shrimp, or veggies, something’s up.

Sure, some turtles eat less in colder months or during shedding. But if your turtle skips more than two meals in a row, or hasn’t eaten for several days, it could point to:

Respiratory infection
Mouth or throat issues
Stress or tank problems
Parasites or internal illness

I’ve found that warm water soaks and adjusting basking temperatures sometimes help — but if it continues, I always follow up with a reptile vet.

2. Swollen Eyes or Eyelids

This is a big red flag. My turtle once had swollen, puffy eyelids — and it didn’t open its eyes for days. Turns out, it was due to a vitamin A deficiency and poor water quality.

If your turtle’s eyes look:

Puffy
Cloudy
Sealed shut
Constantly watering

…it’s likely fighting an infection or deficiency. I had to clean the tank thoroughly, adjust the UVB lighting, and start vitamin-rich food (or even injections in serious cases).

3. Lethargy or Weakness

Turtles are chill by nature, but they’re not statues. When my turtle stopped swimming, basking, or reacting to anything — I knew something was wrong. A healthy turtle should:

Bask daily
React to sound or motion
Move away when touched

If your turtle seems sluggish, sits in one spot for hours, or stays underwater all day without basking, check water temps and UVB exposure. And yes, a vet visit might be needed to rule out deeper issues like infection or internal illness.

4. Shell Problems or Discoloration

When I first noticed weird spots on my turtle’s shell — I thought it was just dirt or shedding. But those soft, white, or smelly patches? That’s not normal. Shell issues are one of the clearest signs your turtle might be sick.

Look out for:

Soft spots (especially in older turtles)
Discoloration — white, pink, black, or green patches
Flaking or peeling
Bad smell or mushy areas

These symptoms can point to shell rot, fungal infections, or nutritional deficiencies. In my case, it was early shell rot from dirty water and lack of proper basking. I had to clean the area daily, keep the shell dry during treatment, and improve tank hygiene and UVB lighting.

5. Trouble Breathing (Respiratory Infections)

Turtles are prone to respiratory infections, especially if their environment isn’t warm enough. One of the scariest moments I had was when I saw my turtle gasping for air and floating oddly.

Signs of a respiratory infection include:

Gasping or wheezing
Bubbles from the nose or mouth
Lopsided or tilted swimming
Constantly staying out of the water

This is a serious emergency. Don’t wait it out — I immediately took mine to a reptile vet and got antibiotics. If untreated, a respiratory infection can be fatal.

6. Diarrhea or Unusual Poop

Let’s be honest — no one enjoys checking turtle poop. But it tells you a lot about their health. I once noticed my turtle had runny, off-colored waste, and sure enough, it was battling a mild parasite issue.

Red flags in poop:

Watery or very loose
Off-color (yellow, green, or gray)
Contains undigested food
Has a foul or unusual smell

Changes in diet can cause this short-term. But if it persists, I always consider parasites or digestive issues and seek a stool test from a vet.

7. Unusual Swimming or Floating

Healthy turtles swim with balance. If you see weird swimming patterns like:

Floating to one side
Sinking and struggling to rise
Spinning or uncoordinated movement

…it might be more than just playtime. Mine floated sideways once — it turned out to be gas buildup from poor digestion, but it could also mean respiratory issues or swim bladder problems.

8. Lack of Basking

Turtles need to bask to regulate their body temperature and absorb essential UVB rays. If your turtle suddenly stops basking, something’s probably off.

From my experience, common reasons include:

Water or basking platform too cold
Inadequate lighting
Illness or discomfort
Stress from poor tank conditions

When mine stopped basking, I checked the temperature and realized the bulb had burned out. After replacing it and adjusting the heat lamp position, things went back to normal. But if your turtle still avoids basking after fixing those basics — it’s time to consider a health check.

9. Weight Loss or Noticeable Weakness

It can be hard to tell if a turtle’s losing weight under its shell — but you can spot it in how the skin looks around the limbs, or if the turtle becomes visibly bonier and weaker.

In my case, weight loss showed up alongside poor appetite and sluggish movement. It turned out to be a parasite issue and low temps affecting digestion.

If you notice:

Loose or sagging skin
A sunken or “shrinking” look
Muscle weakness or refusal to move

…don’t wait. A vet visit, fecal test, and nutritional support are the next best steps.

What To Do If You Think Your Turtle Is Sick

Here’s what I always recommend based on my own experience:

Isolate the problem — Check the lighting, heating, water cleanliness, and basking setup first. Most issues start there.
Monitor closely for 24–48 hours — Watch their behavior, appetite, and activity.
Improve diet and supplements — Offer dark leafy greens, high-quality pellets, and add a calcium source.
Keep things clean — Poor hygiene = infections.
See a reptile vet if symptoms worsen or don’t improve.

FAQs

1. Can turtles get colds?

Yes, they can get respiratory infections — basically the turtle version of a cold. It’s usually caused by cold temperatures, dirty water, or stress.

2. How do I know if my turtle has parasites?

Unusual poop, weight loss, and lack of appetite are the big signs. A vet can do a fecal test to confirm and prescribe treatment.

3. Can turtles heal on their own?

Sometimes, minor issues resolve with good care — but many turtle illnesses need intervention. Don’t wait too long to get help.

Final Thoughts

Turtles may seem low-maintenance, but trust me — their health can change fast, and they won’t always show it clearly. I’ve learned that the smallest changes in behavior or appearance can be early signs of illness.

If your turtle is acting strange, stop and look closely. Check the setup. Watch their eating and basking habits. And most importantly — don’t hesitate to get expert help. I’ve saved my own turtle’s life more than once just by catching the signs early.

Got a story or question about your turtle’s health? Drop it in the comments — I’d love to hear it and help if I can.