Evaluation of decompression illness is based on a history and physical examination. The type, length and depth of dive is important to know for treatment.

Physical findings in someone with decompression illness may include:

• Skin bruising or rash
• Subcutaneous emphysema:
• Air in the soft tissues that gives a spongy quality to the tissue
• Tenderness of the muscles
• Joint tenderness
• Neurological deficits such as:
• Numbness on one side of the body
• Weakness on one side of the body
• Balance problems
• Difficulty walking

The diagnosis of decompression illness is usually made without testing.

Tests that may be used to evaluate decompression illness include:

• CT scanning of the brain
• MRI scan of the brain