Diffuse Idiopathic Skeletal Hyperostosis (DISH)

Overview

Diffuse idiopathic skeletal hyperostosis, usually shortened to DISH, is a condition in which the ligaments and tendons that attach to the spine gradually calcify and turn into bone. Over time this creates flowing bands of new bone along the vertebrae, most often in the middle (thoracic) part of the back. It can also affect the neck, lower back, and areas where tendons attach elsewhere in the body, such as the heels and elbows.

Unlike many other spinal conditions, DISH is not caused by joint inflammation and does not erode the joints. The word "idiopathic" means the exact cause is unknown. Many people have no symptoms and learn they have DISH only when an X-ray is taken for another reason, while others develop stiffness and discomfort.

Symptoms

DISH often causes no symptoms, particularly in its early stages. When symptoms do occur, they may include:

• Stiffness and tightness in the back, frequently worst in the morning or after long periods of rest
• Back pain or neck pain, usually mild to moderate
• Reduced range of motion and difficulty bending or twisting the spine
• Pain at the heels, shoulders, elbows, or knees where tendons attach to bone
• In the neck, large bony growths can rarely press on the esophagus and cause difficulty swallowing or a hoarse voice

Causes

The cause of DISH is not known. It is not an inflammatory or autoimmune disease. Instead, the body lays down extra bone in the soft tissues that attach to the skeleton, especially along the spine. Researchers believe metabolic factors are important, because DISH is strongly associated with conditions such as type 2 diabetes, obesity, and high insulin levels, which may promote bone growth in these tissues.

The new bone formation builds up slowly over years. Because it develops gradually, the spine can become noticeably stiffer before a person is aware of any change.

Risk Factors

• Older age, with the condition becoming more common after age 50
• Being male
• Type 2 diabetes or high insulin levels
• Obesity and metabolic syndrome
• Long-term use of certain medications, such as some acne treatments that affect bone (in some cases)

Diagnosis

DISH is usually diagnosed with imaging, often after symptoms or an unrelated scan prompt evaluation.

• X-rays: the main test; characteristic flowing bony bridges along several vertebrae, with the disc spaces preserved, point to DISH.
• CT scan: gives a more detailed view and can show bone growth pressing on nearby structures such as the esophagus or airway.
• MRI: sometimes used to assess the spinal canal or nerves if there are neurological symptoms.

A key part of diagnosis is distinguishing DISH from inflammatory spine conditions like ankylosing spondylitis, which it can resemble but which has different X-ray features and causes.

Treatment

There is no cure that reverses the bone growth, so treatment focuses on relieving symptoms and maintaining mobility.

• Pain relief: acetaminophen or anti-inflammatory medicines (NSAIDs) for stiffness and discomfort.
• Physical therapy: stretching and range-of-motion exercises help keep the spine and other joints as flexible as possible.
• Heat and activity: gentle activity, warm compresses, and good posture can ease morning stiffness.
• Managing related conditions: controlling diabetes and body weight is encouraged and may help overall health.
• Surgery: rarely needed, but may be considered if large bony growths cause serious swallowing difficulty or press on nerves or the spinal cord.

Prevention

Because the cause is unknown, DISH cannot be reliably prevented. General measures that support metabolic and bone health may help reduce risk or limit progression:

• Maintain a healthy body weight
• Keep blood sugar well controlled if you have diabetes
• Stay physically active to preserve flexibility and strength
• Eat a balanced diet and avoid smoking
• Keep regular medical check-ups to monitor related conditions

When to See a Doctor

See a doctor if you have persistent back or neck stiffness, pain that limits your activity, or tenderness where tendons attach to bone. Seek prompt medical attention if you develop:

• Difficulty or pain when swallowing, or a sensation of food getting stuck
• New numbness, tingling, weakness, or loss of bladder or bowel control, which can signal pressure on the spinal cord or nerves
• Breathing difficulty linked to neck bone growth

These less common problems need evaluation to rule out pressure on nearby structures.

Related Topics

Frequently Asked Questions

References

1. Mayo Clinic. Diffuse idiopathic skeletal hyperostosis (DISH) — Symptoms and causes.
2. National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS). Spine conditions.
3. MedlinePlus, U.S. National Library of Medicine. Spinal disorders.
4. American Academy of Orthopaedic Surgeons (AAOS). Spine health.