There are numerous diseases that affect the tailbone. According to the U.S. National Library of Medicine and the National Institutes of Health or NIH, the tailbone, also known as the coccyx, is a small bone located under the sacrum at the bottom of the spine 1. Common tailbone symptoms include pain in the tailbone region, pain with sitting, pain or numbness in the arms or legs and a tailbone growth that can be felt or observed.

Chordoma

Chordoma is a disease of the tailbone. According to the Chordoma Foundation--a non-profit organization dedicated to curing chordoma--it is a rare primary malignant bone cancer that manifests in the base of the skull and other portions of the spine, including the tailbone 2. The TCF reports that the incidence of chordoma is one per million per year and that there are about 300 new cases of chordoma each year in the United States. While chordoma affects people of all ages, the average age of onset is 49 years. According to the TCF, chordoma appears in men more often than women. People with chordoma live about seven years after being diagnosed and conventional biomedical treatment methods for chordoma include surgery and radiation. The American Academy of Orthopaedic Surgeons states that chordoma is a slow-growing tumor and that it can spread to other organs, especially the lungs 3.

Coccydynia

Coccydynia is a disease of the tailbone 4. The Cleveland Clinic--one of the top four hospitals in the United States--states that coccydynia is an idiopathic condition of the tailbone that's characterized by pain in or around the coccyx 4. According to the Cleveland Clinic, the most common symptom associated with coccydynia is pain or tenderness in the tailbone when pressure is placed on involved area 4. Other common symptoms include severe pain when shifting from a sitting to standing position, pain during defecation, pain during sexual intercourse and a deep, dull ache in the region of the coccyx. The Cleveland Clinic states that coccydynia symptoms typically abate with standing or walking, when pressure is removed from the tailbone 4.

Pilonidal Cyst

A pilonidal cyst is a disease of the tailbone 5. According to the Mayo Clinic website, a pilonidal cyst is an unusual pit or pocket in the skin overlying the tailbone, near the top of the buttocks' cleft, and pilonidal cysts often contain hair and other abnormal tissue 5. The Mayo Clinic website states that pilonidal cysts are more common in men and young adults and that unless a pilonidal cyst becomes infected, it's usually harmless 5. However, if a pilonidal cyst does become infected, it can form a pilonidal abscess, which may require surgical drainage 5. According to the U.S. National Library of Medicine and the National Institutes of Health or NIH, there does not appear to be a definitive cause of pilonidal cysts, although some experts believe that genetics and ingrown hairs may be contributing factors 1. Common symptoms associated with pilonidal cysts include the following: pain, swelling and inflammation in the involved area, drainage of pus or blood from a skin opening and fever, among other symptoms.