You get coccydynia when your coccyx, or the surrounding tissue, is damaged. This causes pain and discomfort at the base of your spine, particularly when sitting down.

The coccyx can be damaged in various ways, although in many cases it's not possible to identify a cause.

The main causes of coccydynia include:


Giving birth is one of themost common causes of coccydynia.

The coccyx becomes more flexible towards the end of pregnancy. This allows your coccyx, and the part of your spine above it, to bend and give way when you give birth.

Sometimeschildbirth can cause the muscles and ligaments (stretchy tissue that connects bones) around your coccyx to overstretch. This can result in coccydynia.

Injuring your coccyx

You can injure your coccyx if you suffer a hard impact to the base of your spine. For example, from an accidental kick during contact sports.

Falling backwards is another common cause of injury to the coccyx.

In most cases where the coccyx is injured, it will only be badly bruised. But in more severe injuries, it may bedislocated (out of place) or fractured (broken).

Repetitive strain injury (RSI)

You may get coccydynia if you regularly take part in sports such as cycling or rowing. This is due to continually leaning forward and stretching the base of your spine.

If this motion is repeated many times, the muscles and ligaments around your coccyx can become strained and stretched.

Strainingyour muscles and ligaments can permanently damage them. If this happens, your muscles will no longer be able to hold your coccyx in the correct position, causing pain and discomfort.

This causes pain and discomfort that will get worse the longer you stay in this position.

This can cause coccydynia or make existing coccydynia worse.

You may also develop coccydynia if you are very slim. If this is the case, you may not have enough buttock fat to prevent your coccyx from rubbing against the tissues surrounding it.

You can use the body mass index (BMI) calculator to find out whether you are a healthy weight for your height.


As we grow older the small discs of cartilage (a tough, flexible tissue) that help hold the coccyx in place can wear down. The bones that make up the coccyx can also become more tightly fused together. This can place more stress on the coccyx, leading to pain.


Rarely an infection can occur in the base of the spine or soft tissue and cause coccydynia, such as a Pilonidal sinus (a painful collection of pus that usually develops in the cleft of the buttocks).


A less common cause of coccydynia is cancer. This can be bone cancer or cancer that starts somewhere else in the body and then spreads into the bone (metastatic cancer).

Joints are the connection point between two bones that allow movement.
Ligaments are made of fibrous tissue. They connect bone to bone, providing support while allowing flexibility and movement.
Pain is an unpleasant physical or emotional feeling that your body produces as a warning sign that it has been damaged.
The spine supports the skeleton, and surrounds and protects the delicate spinal cord and nerves. It is made up of 33 bones called the vertebrae.
Body tissue is made up of groups of cells that perform a specific job, such as protecting the body against infection, producing movement or storing fat.
Content supplied by the NHS Website

Medically Reviewed by a doctor on 26 Jul 2016