Why is my Chameleon Leaning to One Side?

Have you ever noticed your chameleon leaning to one side under their basking lamp? Or have you seen them flattening their body, turning dark on one side, and then facing their basking lamp with only the dark side of their body? What’s this all about?

Why is my chameleon leaning to one side? Your chameleon is leaning to one side to expose more of their body to the warmth of their basking lamp. This is called lateral basking and is common among chameleons. Be sure that your chameleon’s basking and cool areas are kept at the appropriate temperatures.

If you notice that your chameleon is leaning to the side while moving around their enclosure, or that they seem to be suffering from muscle weakness, an inability to stand, and an overall lack of coordination, these could be signs of metabolic bone disease. If this is the case, you should call your veterinarian immediately.

Chameleon Basking

photo provided by Kayla

Chameleons are cold-blooded creatures, and are also Heliothermic. This means that they get heat directly from the sun’s rays (or in the case of captivity, their basking lamp), rather than obtaining heat by touching or lying on warm objects.

Since chameleons are arboreal, meaning they live primarily in trees, they have developed certain methods to make them particularly efficient Heliotherms. 

First, chameleons bask laterally by positioning their body towards the sun or their heat lamp in such a way that enables them to expose the maximum amount of surface area to the heat source.1 Chameleons also have hinged ribs, which enable them to flatten their bodies and increase the surface area of the part of their body that is currently exposed to the heat source.

Finally, chameleons darken the portion of their body exposed to their heat source to increase heat absorption. They may also lighten the side of their body that is not currently exposed to heat to more adequately retain any remaining heat in that area. 

Much like other reptiles, chameleons need the proper amount of exposure to UV-spectrum light for good health, both physical and mental. Chameleons exposed to ultraviolet light illustrate increased social behavior, activity levels, and appetite.2 An absence of this type of light can contribute to health problems such as metabolic bone disease.

Chameleon Temperature, Humidity, and Light Requirements 

The proper conditions for your pet chameleon will vary a bit based on their species. For the purposes of this article, I’ll highlight the requirements for Jackson’s chameleons and veiled chameleons.

Veiled chameleons are originally from Saudi Arabia and Yemen in the Middle East. More recently, these chameleons have established smaller populations in “tropical” areas of the United States, such as Hawaii and Florida, where they are considered to be an invasive species.

To mimic their natural habitat, you should aim to keep your veiled chameleon’s ambient temperature between 72-80°F. The basking temperature of a veiled chameleon’s enclosure should be between 85-93°F. At night, the temperature in your veiled chameleon’s tank should be somewhere between 65-70°F. You should also keep the relative humidity of their enclosure around 50%.

Jackson’s chameleons, on the other hand, are native to Kenya and Tanzania, Africa. They have also invaded the Hawaiian islands. In the wild, Jackson’s chameleons inhabit cool, humid mountain slopes where there is frequent rainfall. Research data suggests that they prefer areas with daytime temperatures that range from 61-81°F.

Based on their natural preferences, the captive temperature requirements for a Jackson’s chameleon are a bit cooler than those for veiled chameleons. The basking area for a Jackson’s chameleon should be about 83°F.

The cool side of their enclosure should be about 68-72°F, and nighttime temps should be kept between 50-59°F. Chameleons of any type are typically found to be healthier when you allow the temperature of their environment to drop at night. 

Jackson’s chameleons require high humidity levels at night, and lower levels of humidity during the day. In the wild, the humidity in their habitat is as high as 100% at night, and around 30% during the day. You should attempt to mimic these conditions as closely as possible for your captive chameleon using a mister.

The best basking bulbs for chameleons are typically 75W and 100W. Be sure to place your reptile’s bulb at least 6-7 inches above the basking spot so it does not burn your pet.

You can measure the temperatures on both sides of your chameleon’s habitat using reliable digital thermometers. You can also use an infrared thermometer to spot check your chameleon’s basking surface and ensure that it isn’t too hot or too cool. You can also measure the humidity levels in your chameleon’s tank using a digital hygrometer on each side of the tank.

In addition to a basking or heat lamp, chameleons of all species need exposure to full spectrum ultraviolet light (UVA/UVB) for 10 to 12 hours per day. Chameleons and other reptiles need this type of light to manufacture Vitamin D, which is essential to the absorption of calcium and therefore, good bone health. You can provide this type of light using a full-spectrum light bulb.

Signs of Healthy and Unhealthy Chameleons

When chameleons consistently receive insufficient amounts of UVA and UVB light, or if they are exposed to improper temperatures for long periods, they can begin to develop several health problems.

As previously mentioned, chameleons and other reptiles need regular exposure to full-spectrum light in order to manufacture vitamin D3. They use vitamin D3 to absorb calcium from their food into their bodies.

If chameleons do not absorb enough calcium, they run the risk of developing metabolic bone disease, which can cause a host of ailments including soft, weak bones that are prone to fractures, as well as organ damage.

Chameleons can also contract respiratory infections as a result of low temperatures, improper humidity levels, and poor ventilation in their enclosure. Symptoms of a respiratory infection can include foamy saliva, bubbles around the mouth, runny discharge from the nostrils, crackling sounds while breathing, gasping, swollen eyes or forehead, and “snoring” during sleep.

If your reptile exhibits any of these symptoms, do not attempt to treat their infection on your own. Call your veterinarian immediately so they can provide an antibiotic, determine the cause of the infection, and give you instructions on how you can improve your chameleon’s living conditions so they do not develop another infection in the future.

In addition, low humidity, inadequate misting, and lack of UVB light can cause mouth rot, also known as Stomatitis, in chameleons. Symptoms of mouth rot include red, swollen lips, sticky mucus, excess saliva or discharge on your chameleon’s lips, and dark “plaque” on their teeth.

If your chameleon’s mouth rot does not resolve on its own, consult your veterinarian about whether you should attempt an at-home treatment or make an appointment for your chameleon.

Be sure to clean your chameleon’s habitat on a regular basis. Dirty, unsanitary conditions can also contribute to poor reptile health. You should spot-clean, removing any waste or uneaten food, every day.

At least once a month, you should remove your chameleon and all objects, such as plants, rocks, dishes, and substrate, from the enclosure, and thoroughly clean the tank. Soak tank decorations in warm water and mild disinfectant, or scrub them with soapy water. You can spray off live plants and trees using clean water, then place them in the sun to dry.

Healthy chameleons who are kept in clean enclosures, fed a proper diet, have regular exposure to full-spectrum light, and are kept at the appropriate temperature and humidity levels will be active and alert. They will also display the following signs of good health:

  • Clear eyes that are round and rotate well
  • Good balance
  • Body and tail appear well-filled out
  • Skin and scales appear healthy; no old skin attached; can shed old skin quickly
  • Proper body size for their age
  • Crest that is the right size for the chameleon’s age and sex
  • Alert and responsive
  • Display bright colors, no consistent grey or dark green
  • Clear nose and vent
  • Healthy appetite


Chameleons have a unique way of basking and leaning or flattening their bodies while basking is not an immediate cause for concern. If your pet chameleon is displaying any other signs of illness, however, you should call a licensed reptile veterinarian immediately.

As with all captive reptiles, proper husbandry is essential for the maintained good health of your chameleon. Be sure you are keeping your chameleon’s habitat clean, maintaining the appropriate temperature and humidity levels, and that you are providing them with regular exposure to full-spectrum light. You should also be feeding your chameleon a proper diet and supplementing with calcium as necessary.


  1. https://ectotherms.fandom.com/wiki/Chameleon_-_S.S#:~:text=Chameleons%20are%20only%20Heliothermic.&text=Chameleons%20take%20this%20principle%20several,area%20to%20the%20heat%20source.
  2. https://en.wikipedia.org/wiki/Chameleon 
  3. https://www.thecritterdepot.com/blogs/news/veiled-chameleons#Temperature-and-Humidity

I’m Devin Nunn, an average joe that just so happens to have a deep love and passion for everything to do with reptiles. Because taking care of them for the vast majority of my life wasn’t fulfilling enough, I decided to begin educating others about them through my articles. read more...