When ultrasensitive C-reactive protein 100 mg/L is high, it is commonly seen in various purulent inflammatory diseases in the body, such as purulent appendicitis, purulent tonsillitis, and urinary tract infections or lobar pneumonia. Ultrasensitive C-reactive protein of 100 mg/L is also seen in rheumatoid arthritis, especially in the acute active phase of rheumatic fever. In addition, it is important to note that tissue necrosis can also lead to a significant increase in C-reactive protein, such as in the case of severe trauma, extensive burns, or myocardial infarction. In the case of malignant tumors, such as liver cancer, lung cancer, stomach cancer, and intestinal cancer, C-reactive protein can also be significantly high, so it is important to analyze specific problems.