The diabetes disease burden in China is heavy, and medical standards such as diabetes guidelines are the core reference guidelines for diabetes management for health care providers and patients. However, patients' guideline compliance is too low, which correlates with the gap between guidelines and patients' self-management needs. Incorporating patient needs into the guideline development would reduce this gap. We sought to capture the needs of patients with diabetes for self-management in everyday situations and to clarify the contradictions and misalignments between medical standards, such as guidelines, and patient needs. This study collected crawler-based data from 4 online health communities. We selected 1605 text records collected from Chinese patients with diabetes between March 2020 and July 2020 for analysis. The text analysis applied grounded theory to separate issues that concerned patients into 3 themes, 7 subthemes, and 25 entries. Altogether, 69.03% (1108/1605) of texts were related to issues concerning disease treatment (theme B) and mainly inquired about medication use (B2 and B3; 686/1108, 61.91%), including medication choice, change in medication administration, side effects, and postmedication effects. In addition, 222 (N=1605, 13.8%) texts (theme A) concerned the explanation of disease etiology and knowledge of diabetes, and 275 (N=1605, 17.1%) texts (theme C) discussed lifestyle changes and various restrictions on life brought about by the disease. Our findings suggest an urgent need to improve diabetes health education and guideline development strategies and to develop health management strategies from a patient perspective to bridge the misalignment between patient needs and current medical standards.