Electromagnetic radiation (EMR), spanning a vast spectrum from extremely low-frequency (ELF) waves to highly energetic ionizing forms such as X-rays and gamma rays, has become increasingly pervasive in today’s world. The rapid advancement and widespread use of wireless communication systems, electrical appliances, and medical imaging technologies have amplified human exposure to EMR. This review examines how such exposure impacts human biology and health, emphasizing the differences between ionizing and non-ionizing radiation. Non-ionizing radiation—originating from devices like mobile phones, Wi-Fi routers, and microwave transmitters—has been linked to potential thermal and non-thermal biological changes, including oxidative stress, altered cellular function, and neurological symptoms. In contrast, ionizing radiation is well known for its ability to cause DNA damage, mutations, and cancer. Although international safety limits has been established based on existing evidence, emerging research points toward a need for revising these standards, especially concerning prolonged low-level exposure to non-ionizing radiation. This paper summarizes current findings, identifies knowledge gaps, and underscores the necessity of sustained multidisciplinary research to better understand long-term EMR health implications.