Comprehensive medical evidence forms the foundation of successful Social Security disability claims documenting severity and functional limitations. Treatment records from all providers establish diagnosis, symptoms, and response to treatment. Diagnostic test results including imaging, laboratory work, and specialized studies provide objective findings. Physician statements describing specific functional limitations carry significant weight. Mental health records require detailed session notes beyond just diagnoses and medications. Hospitalization records demonstrate condition severity through acute care needs. Therapy notes document ongoing limitations despite treatment attempts. Medication lists with side effects impacting function support disability. Work records showing attendance problems and performance issues corroborate inability. Educational records help establish cognitive limitations for younger applicants. Daily activity forms completed honestly avoid credibility problems. Third-party statements from family describing observed limitations provide support. Vocational reports analyzing transferable skills strengthen older worker claims. Understanding evidence requirements helps build strong cases avoiding common denial reasons.