PURPOSE OF THE REVIEW: To provide an overview of diagnostic tests for Stage B heart failure (SBHF), synthesizing evidence from guidelines and clinical studies. RECENT FINDINGS: Advances in diagnostic technologies have expanded the ability to identify subclinical myocardial remodelling and early myocardial injury before symptom onset. We highlight the central role of transthoracic echocardiography as the cornerstone diagnostic modality for detecting subclinical myocardial remodelling and dysfunction, including the use of speckle tracking echocardiography. In parallel, circulating biomarkers, especially natriuretic peptides and high-sensitivity cardiac troponins, can play important roles in the detection and risk stratification of SBHF. Additional diagnostic approaches, including electrocardiography, chest X-ray, cardiac magnetic resonance imaging, cardiac computed tomography, nuclear imaging, and exercise stress testing, are reviewed for their adjunctive roles in selected clinical contexts. Emerging applications of artificial intelligence are explored as promising strategies to increase the diagnostic precision, scalability, and early detection of SBHF in clinical practice. SBHF - representing a subclinical phase of HF characterized by structural cardiac abnormalities, functional impairment, or persistently abnormal cardiac biomarkers in individuals - has historically been difficult to recognize in the community. Advances in imaging, biomarkers, and AI may improve the feasibility of detecting this entity, creating a crucial window for intervention, because timely risk stratification and preventive strategies during SBHF may attenuate progression to symptomatic HF and reduce its long-term clinical and economic burden.