What is the hallmark of Type I pain experienced in decompression sickness?

The hallmark of Type I pain experienced in decompression sickness is characterized as gradual and dull. This type of pain typically results from nitrogen bubble formation in the tissues, which can cause a sensation that is uncomfortable but not acutely sharp or severe. Type I decompression sickness, also known as "the bends," often involves musculoskeletal pain or discomfort that develops over time, rather than an instant, sharp pain.

In distinguishing Type I pain, it is important to recognize that it usually presents as a dull ache in the joints or muscles and may worsen gradually as the condition develops. This contrasts with other types of pain that may be more severe or sudden in nature. Understanding the characteristics of Type I pain is essential in identifying and responding appropriately to decompression sickness during diving operations.