Poor posture negatively impacts health, leading to muscle strain, joint pain, misalignment of spine, reduced circulation, and impaired lung function. It contributes to fatigue, headaches, digestive issues, and exacerbates pre-existing conditions like arthritis. Additionally, poor posture affects mood, self-esteem, and workplace productivity. Regular exercise, ergonomic adjustments, and practicing correct sitting, standing, and walking positions are essential to prevent these detrimental effects.