The tailbone, or coccyx, is a small bony structure at the bottom of your spine. It’s made of three to five segments that form a triangular shape.
Although the tailbone is small, it’s an important structure. It’s the attachment site for many ligaments, tendons, and muscles, including those that support the pelvic floor and control bowel movements. The tailbone also provides support when you’re sitting.
In humans, the tailbone develops from an actual tail. During the first 4 to 6 weeks of development, a human embryo has a tail with 10 to 12 vertebrae. At 8 weeks, the vertebrae fuse together and form the tailbone.
Prior to MRI imaging, it was accepted that the tailbone was comprised of only one bone. Since then, it has become understood that the coccyx is typically comprised of three to five segments, though that varies from person to person.
The size of a tailbone, like other bones, can also vary from person to person. Some people might have longer tailbones than others. The tailbone might also look like it’s sticking out after weight loss or injury.
A protruding tailbone usually isn’t a medical issue. But if it causes symptoms like pain, you may need treatment.
Read on to learn about the potential causes of a protruding tailbone, along with treatment options.
Possible symptoms of a protruding tailbone include:
- visible, hard bump above the butt
- pain when sitting or lying down
- lower back pain
- swelling in the area
Depending on the cause, a protruding tailbone might not cause any symptoms.
There are several potential causes of a protruding tailbone. Possible conditions include:
Tailbone misalignment due to severe injury
Severe physical trauma can misalign or dislocate the tailbone. This may cause the tailbone to stick out.
Typically, injuries that lead to tailbone misalignment involve falling on your bottom. They also involve extreme physical force.
Examples of these injuries include:
- falling backward on a hard surface (like the floor or an icy sidewalk)
- slipping backward on the stairs
- landing on your bottom from a high level
The more severe the injury, the more likely it is to cause tailbone misalignment. Otherwise, in most cases, these injuries will only cause bruising and pain.
Rapid weight loss
According to a 2014 study, there are anecdotal reports of rapid weight loss reducing the cushioning around the tailbone. This could make the tailbone more visible and look like it’s sticking out.
In some people, genetics could be a factor. If your parents naturally have a protruding tailbone, you may have one, too.
Hyperlordosis occurs when the lower spine excessively curves inward. This pushes your pelvis back and up, potentially making your tailbone stick out.
The condition also causes the stomach to curve outward. Possible causes of hyperlordosis include:
During pregnancy, the excess weight of the baby adds pressure to the tailbone. This can cause pain and discomfort in the area.
Just before you give birth, the tailbone becomes more flexible. The increased flexibility lets the muscles and ligaments attached to the tailbone stretch while you give birth.
After childbirth, these muscles and ligaments may become overstretched. This could lead to pain and swelling, making your tailbone more visible.
The process of childbirth can also dislocate or fracture the bone, leading to a protruding tailbone.
If your tailbone is sticking out and causing no symptoms, you typically don’t need treatment.
Treatment may be necessary if you have:
- persisting or worsening pain
- severe swelling
- numbness in one or both legs
- difficulty sitting or lying down
- pain that makes it difficult to do daily activities
- trouble passing bowel movements
- protruding tailbone after experiencing an injury
- symptoms that fail to improve with home remedies
- pain that spreads to other parts of the body
Treatment depends on the cause of a protruding tailbone. Options include:
Stretches may improve symptoms caused by a protruding tailbone.
Specifically, tailbone stretches can help improve spinal alignment. Stretches can also reduce pressure on the tailbone by relaxing the muscles, ligaments, and tendons attached to it.
If stretching at home fails to treat your symptoms, a doctor may refer you to a physical therapist.
A physical therapist can:
- perform massages to reduce tailbone pain
- teach you stretches and exercises to improve spinal alignment
- recommend body movements to reduce tailbone discomfort
Injectable dermal fillers are gel-like substances that add volume to the skin. They might make a protruding tailbone less noticeable when injected in the surrounding area.
But not everyone is a good candidate for dermal fillers. There’s also no research proving that dermal fillers are effective for protruding tailbones.
In severe cases of tailbone protrusion causing pain, there are more invasive treatments such as dermal fat grafts to pad the surrounding area. Another option is coccygectomy, which is the removal of a portion or all of the tailbone. However, these treatments can have several post-operative complications, including:
- pelvic floor prolapse
- continued pain
If you’re curious about these options, talk with a doctor to see if they’re right for you.
A protruding tailbone can happen due to genetics, a curved spine, or simply having a longer tailbone. If it’s causing no symptoms, it’s not a medical emergency.
However, if your tailbone is sticking out and painful, it’s best to see a doctor. They can determine the cause and recommend treatment.
You should also get medical help if your tailbone is protruding after giving birth or sustaining an injury.