Dementia is a severe condition affecting more than 55 million people worldwide. In elderly patients, it leads to an overall decline in memory and thinking skills. It affects the patient and those around the patient, including family and caregivers. The symptoms can become so severe that the person's ability to perform everyday activities becomes compromised. This study aims to search and collect information about the sensitivity and specificity of available laboratory diagnostic methods for patients with Dementia and identify if these methods will be effective in giving a specific and definitive diagnosis. The specificity and sensitivity of four main laboratory testing methods have been included in this review: blood panels, cerebrospinal fluid, plasma biomarkers, hormone testing, and genetic testing. The methods are each explained separately with details of their importance and which specific parameters they screen for have haven included. Numerous blood panels and laboratory diagnostic techniques have been suggested for the timely and accurate diagnosis of Dementia and its various types; however, when the sensitivity and specificity of these techniques are considered, cerebrospinal fluid (CSF) and plasma biomarkers are found to be the most effective. Alzheimer's disease (AD) and other types of Dementia are now diagnosed using the biomarkers amyloid- (A), tau, and phosphorylated tau (p-tau181). With 93 percent accuracy in diagnosis, the innovative Precivity AD test created by the Washington University School of Medicine in St. Louis might be regarded as both highly sensitive and specific.