What are the main types of machine learning used in healthcare?

The three main types are: Supervised learning (learning from labelled input-output pairs for classification or regression tasks, e.g. cancer grading, deterioration prediction), Unsupervised learning (finding patterns without labels, e.g. identifying disease subtypes or patient clusters), and Reinforcement learning (sequential decision-making through interaction with an environment, e.g. dynamic treatment regimes for sepsis or adaptive insulin dosing). Supervised learning is the most widely deployed in clinical AI.