In the field of medical diagnosis and treatment, medical images are essential, and their security is critical to ensuring their validity and integrity. Watermarking has become a potential method for protecting digital medical images as their use has grown. To enable copyright protection, tamper detection, and content verification, watermarking entails putting an undetectable mark onto the image. Throughout the literature, a variety of watermarking methods have been suggested, each having advantages and drawbacks of its own. Discrete Wavelet Transform (DWT), Discrete Cosine Transform (DCT), Principal Component Analysis (PCA), Singular Value Decomposition (SVD), and Redundant Discrete Wavelet Transform are just a few of the different watermarking methods covered in this paper's thorough review of their applications in medical image security (RDWT). The performance of these algorithms is also compared in this work using a variety of measures, including Peak Signal-to-Noise Ratio (PSNR), Normalized Correlation (NC), Structural Similarity Index (SSIM), and Bit Error Rate (BER). As a result of its great robustness and imperceptibility, PCA is the technique that works best for watermarking medical images, according to the results. The performance of watermarking approaches should be assessed using the right metrics and benchmarking tools, as this paper clearly emphasises. The results of this study can help practitioners and researchers in the field of medical image security select the best watermarking method depending on their unique needs.