1 Costochondritis. 2  In this condition, the cartilage of your rib cage, particularly the cartilage that joins your ribs to your breastbone, becomes inflamed and painful. 3  Sore muscles. 4  Chronic pain syndromes, such as fibromyalgia, can produce persistent muscle-related chest pain. In this condition, the cartilage of your rib cage, particularly the cartilage that joins your ribs to your breastbone, becomes inflamed and painful. 2  Sore muscles. 3  Chronic pain syndromes, such as fibromyalgia, can produce persistent muscle-related chest pain.
For other uses, see Decibel (disambiguation). The decibel (dB) is a logarithmic unit used to express the ratio of two values of a physical quantity. One of these values is often a standard reference value, in which case the decibel is used to express the level of the other value relative to this reference.
Refer is defined as  to direct to for something needed, or to make a reference. An example of refer is for a woman to suggest that her friend visit a specific doctor. An example of refer is to include an in-text citation in a research paper.