The Human Metapneumovirus (hMPV), a member of the Pneumovirinae subfamily, is a substantial cause of acute lower respiratory infections, notably in young children, the elderly, and immunocompromised patients. It was first identified in 2001, hMPV has displayed a seasonal pattern of infection, with symptoms ranging from moderate to severe respiratory disease. This study investigates the worldwide effect of hMPV, concentrating on its transmission, etiology, diagnostics, and treatment techniques, underlining the need for better public health measures. hMPV is spread by respiratory droplets, with a normal incubation period of 3-5 days. The virus induces an immune response characterized by pro-inflammatory cytokines, leading to respiratory symptoms and probable tissue damage. Diagnostic breakthroughs, including RT-qPCR and mNGS, have enhanced detection sensitivity. However, therapy is generally supportive, with potential breakthroughs in mRNA vaccines targeting hMPV fusion proteins. Current clinical studies evaluate the effectiveness and safety of these new vaccinations, which might pave the road for effective prevention. Despite tremendous gains in understanding hMPV, there remains a crucial need for targeted antiviral treatments and vaccines to minimize its worldwide health impact.