To address the challenge that Smart Wearable Medical Devices (SWMDs) lack sufficient computational power for efficient e-Health data transmission, this paper proposes OOR-CP-ABE, a lightweight Ciphertext-Policy Attribute-Based Encryption (CP-ABE) scheme based on fog computing. By analyzing the computational and storage capabilities of patients, SWMDs, and fog nodes, OOR-CP-ABE significantly reduces the computational burden on patients and SWMDs while enhancing ciphertext retrieval efficiency for medical institutions. Compared to traditional CP-ABE with online/offline encryption, OOR-CP-ABE offloads most encryption operations to fog nodes through outsourced encryption, effectively mitigating the computational limitations of SWMDs. Furthermore, unlike conventional outsourced CP-ABE schemes, OOR-CP-ABE eliminates the need for patients to preprocess physiological data, thereby further reducing their computational overhead. Additionally, OOR-CP-ABE integrates an efficient searchable encryption (SE) mechanism that introduces minimal additional computation, outperforming existing schemes in both efficiency and simplicity. Security analysis demonstrates that OOR-CP-ABE is provably secure against Chosen Plaintext Attacks (CPA) and Chosen Keyword Attacks (CKA). Experimental results confirm its advantages for data sharing in e-Health scenarios.