Coccydynia (Tailbone Pain)
Updated: Nov 26, 2020
Coccydynia refers to any type of persistent tailbone pain.
The tailbone, located at the very bottom of the spine, is medically known as the coccyx. Coccydynia is typically felt as a localized pain that usually worsens when sitting or with any activity that puts pressure on the bottom of the spine.
The condition is much more common in women than men. It is usually caused by trauma to the tailbone or surrounding area, such as a backward fall or childbirth. On rare occasions, an infection or tumor can also cause pain in the coccyx.
This article provides an in-depth review of the causes of coccydynia, diagnosis, and both nonsurgical and surgical treatment options.
Coccydynia may be referred to in various terms, such as:
The various terms are all used to describe one set of symptoms in the tailbone that result in either persistent pain or intermittent, activity-related pain.
The goal of coccydynia treatment is usually to reduce pain by keeping pressure off of the tailbone, easing inflammation or muscle tension that add to pain, or reducing pain signals to the brain using medication. A combination of treatments and activity modification usually suffices to control or alleviate tailbone pain.
In rare cases, surgery to remove all or part of the coccyx may be recommended, but the surgery (a coccygectomy) is typically only considered if the pain is severe and at least several months of non-surgical treatment and activity modification has been ineffective in relieving pain.
An estimated 90% of coccydynia cases resolve with non-surgical treatments, and coccyx pain will often get better with conservative treatment.
History of Coccydynia
Coccydynia has a long history of being misunderstood. In the early 1900s, coccydynia was a popular diagnosis for all types of lower back pain. A fairly extreme treatment, the surgical removal of the coccyx (coccygectomy), was commonly undertaken to treat low back pain. At best, this operation had variable results.
General opinion then changed completely, and it was often postulated that since the condition mostly affected women it was in some way related to "neurosis." The assumption was that if the operation did not work, it was because the pain was psychological in origin.
Studies that have measured the efficacy of psychotherapy as treatment for coccydynia have found little success and conclude that coccydynia does exist as a medical condition.
The condition is now considered a valid diagnosis and is treated as such.
Anatomy of the Coccyx (Tailbone)
The coccyx is a triangular arrangement of bone that makes up the very bottom portion of the spine below the sacrum. It represents a vestigial tail, hence the common term tailbone.
Depending on an individual’s development, the coccyx may consist of three to five different bones connected by fused—or semi-fused—joints and/or disc-like ligaments. While it was originally thought that the coccyx is always fused together, it is now known that the coccyx is not one solid bone, but there is some limited movement between the bones permitted by fibrous joints and ligaments.
The coccyx usually moves slightly forward or backward as the pelvis, hips, and legs move. When a person sits or stands, the bones that make up the pelvis (including the coccyx) rotate outward and inward slightly to better support and balance the body.
Function of the Coccyx
Although the tailbone is considered vestigial (or no longer necessary) in the human body, it does have some function in the pelvis. For instance, the coccyx is one part of a three-part support for a person in the seated position. Weight is distributed between the bottom portions of the two hip bones (or ischium) and the tailbone, providing balance and stability when a person is seated.
The tailbone is the connecting point for many pelvic floor muscles. These muscles help support the anus and aid in defecation, support the vagina in females, and assist in walking, running, and moving the legs.
Why Do More Coccyx Injuries Occur in Women Than Men?
Coccydynia is generally much more common in women; some sources from the medical literature find that women are five times more likely to develop coccydynia than men.
The majority of coccyx injuries occur in women because:
A broader pelvic structure, which may decrease the amount of pelvic rotation and leave the coccyx more exposed to injury.
Women tend to place more weight on the coccyx when sitting, which leaves it more susceptible to injury.
Childbirth, which may cause acute damage as the baby moves over the tailbone
Pelvic muscle cramps can also play a role in increased coccyx pain in women. In physical evaluations, women have reported significantly increased coccyx pain during the premenstrual period.
Coccydynia (Tailbone Pain) Symptoms
Tailbone pain is usually accompanied by other, more specific symptoms that can sometimes indicate how pain is occurring. Coccydynia may be further characterized by one or a combination of the following symptoms:
Localized pain and tenderness. Pain is generally confined to the tailbone, and does not radiate through the pelvis or to the lower extremities. Pain is usually described as an aching soreness and can range from mild to severe. Tightness or general discomfort around the tailbone may be constant, or pain may come and go with movement or pressure.
Increased pain with sitting. Coccydynia is generally more intense when weight is placed on the tailbone, as in when a person leans backward in a sitting position. Likewise, sitting on hard surfaces without a cushion (such as a wooden bench or a metal folding chair) or leaning back against a wall puts added pressure on the tailbone, causing pain to worsen.
Pain that is worse when moving from sitting to standing. When moving from a seated position to standing or vice versa, the rotation of the pelvic bones (and muscle movements that assist this rotation) may be painful. It may be difficult to stand or sit, requiring one to lean against something to provide better stability.
Pain that may increase with bowel movement or sexual intercourse. Some patients experience heightened pain during sexual intercourse or defecation, due to the proximity of the coccyx to the anus and genitals.
Symptoms may differ from patient to patient, depending on one’s unique anatomy and the underlying structures causing pain.
Coccyx pain has the potential to become chronic, lasting longer than 3 months, if the bones’ structural instability persists and the surrounding muscles and ligaments continue to be strained, and/or if there is local inflammation.
Coccydynia (Tailbone Pain) Causes
Direct trauma to the tailbone is the most common cause of coccydynia, and usually leads to inflammation surrounding the coccyx, which contributes to pain and discomfort.
There are many cases reported in which pain begins with no identifiable origin (called idiopathic coccydynia).
Coccydynia is typically caused by the following underlying anatomical issues:
Hypermobility, or too much movement of the coccyx puts added stress on the joint between the sacrum and coccyx and on the coccyx itself. Too much mobility can also pull the pelvic floor muscles that attach to the coccyx, resulting in tailbone and pelvic pain.
Limited mobility of the coccyx causes the tailbone to jut outward when sitting, and can put increased pressure on the bones and the sacrococcygeal joint. Limited coccyx movement may also result in pelvic floor muscle tension, adding to discomfort.
In rare cases, part of the sacrococcygeal joint may become dislocated at the front or back of the tailbone, causing coccyx pain.
The above factors may result from an injury to the coccyx, or may develop as idiopathic coccydynia.
Possible Causes of Coccydynia
A diagnosis of coccydynia will usually identify one of the following underlying causes of pain:
Local trauma. A direct injury to the coccyx is probably the most common cause of coccydynia. A fall on the tailbone can inflame the ligaments and injure the coccyx or the coccygeal attachment to the sacrum. Coccygeal trauma usually results in a bruised bone, but may also result in a fracture or dislocation either in the front or back of the coccyx.
Repetitive stress.. Activities that put prolonged pressure on the tailbone, such as horseback riding and sitting on hard surfaces for long periods of time, may cause the onset of coccyx pain. Tailbone pain from these causes usually is not permanent, but if inflammation and symptoms are not managed, the pain may become chronic and cause long-term altered mobility of the sacrococcygeal joint.
Childbirth. During delivery, the baby's head passes over the top of the coccyx, and the pressure against the coccyx can sometimes result in injury to the coccygeal structures (the disc, ligaments, and bones). While uncommon, the pressure can also cause a fracture in the coccyx.
Tumor or infection. Rarely, coccydynia can be caused by a nearby tumor or infection that puts pressure on the coccyx.
Referred coccyx pain. In rare cases pain will be referred to the coccyx from elsewhere in the spine or pelvis, such as a lumbar herniated disc or degenerative lumbar disc.
Certain factors may increase the chance of coccygeal pain developing. Risk factors for coccydynia include:
Obesity. Pelvic rotation, including movement of the coccyx, is usually lessened in individuals who are overweight, leading to more continual stress being placed on the coccyx and increasing the chances of developing coccyx pain. One study found that a Body Mass Index (BMI) of more than 27.4 in women and 29.4 in men increases the risk for coccydynia following repetitive stress or a one-time injury.
Gender. Women have a higher chance of developing coccydynia than men, due to a wider pelvic angle as well as trauma to the coccyx endured during childbirth.
If pain is mild or moderate, it may not be necessary to identify the exact cause of coccydynia. In some cases, however, coccyx pain is severe or of a serious origin, so it is important to have a general idea why pain has developed so that it can be treated most effectively.
Diagnosis of Coccydynia (Tailbone Pain)
Coccydynia is typically diagnosed by gathering a thorough medical history and completing a physical exam. These two standard diagnostic practices are usually sufficient in obtaining a diagnosis and evaluating treatment options, but in some cases, diagnostic tests such as scans or injections may be used.
Initial Diagnostic Methods for Coccydynia
A complete medical history collected will likely include information on current symptoms, as well as when and how symptoms developed. A doctor may also look for environmental or lifestyle factors for the patient’s pain, such as recent injury, exercise habits, or obesity.
After a medical history is collected, a doctor will begin a physical exam. A thorough physical examination for coccyx pain may include:
Palpation to check for local tenderness. A doctor will feel by hand (called palpation) to identify swelling and tenderness around the coccyx. Palpation may also be used to identify potential coccygeal spicules (bone spurs), cysts, or tumors.
Intrarectal exam and manipulation. In some cases, a doctor may choose to manipulate the coccyx manually through the rectum, in order to assess limited or excessive mobility of the sacrococcygeal joint. Intrarectal manipulation may also be used to assess any muscle tension in the pelvis connecting to the coccyx.
The most consistent finding on examination is usually tenderness upon palpation of the coccyx. If the coccyx is not tender to palpation, then the pain is likely referred from another part of the spine.