Survivors of tuberculosis (TB) may face increased risks of acute and chronic health conditions after completing anti-TB therapy. However, few cohort studies in high-TB burden countries have systematically examined changes in morbidity patterns before and after treatment. Current criteria for determining treatment completion rely on standard treatment duration, sputum culture, or acid-fast bacilli (AFB) smear conversion. However, these indicators may not fully capture long-term clinical outcomes.Objective: To assess changes in the monthly number of diagnosed cases and hospital admission rates for lower respiratory tract infections (LRTIs), chronic respiratory diseases (CRDs), and diabetes mellitus (DM) before and after TB treatment.Methods: A retrospective cohort of patients who survived during TB treatment was linked to the Health Data Center (HDC), managed by the Ministry of Public Health, Thailand. Diagnoses recorded during the “pre-TB” period (–30 to –6 months before treatment) and the “post-TB” period (+6 to +30months after treatment) were identified using ICD-10 codes and categorized as LRTIs (J12–J18), CRDs (J40–J47), or DM (E10–E14). Monthly diagnosis rate ratios (IRRs) and hospital admission IRRs (post- vs. pre-TB) were calculated with 95% confidence intervals (CIs) using a Poisson Regression model.Results: A total of 757 patients were analyzed. The monthly number of LRTIs diagnosis increased non-significantly after TB treatment (IRR 1.38; p = 0.091), while hospital admissions rose markedly (IRR 15.20; p = 0.008). CRD diagnosis nearly doubled post-TB compared to pre-TB (IRR 2.42; p < 0.001), with a fivefold increase in admission risk (IRR 4.90; p < 0.001). DM diagnosis increased by 36% post-TB (IRR 1.36; p < 0.001) and remained elevated throughout follow-up.Conclusions: These findings highlight the importance of incorporating long-term clinical indicators into TB care. Such indicators may support more individualized treatment durations and improved patient outcomes.