We conducted many model simulations to understand the causes of the damages of coronavirus to lung tissues and constructed a diagram showing viral development, immune response and damage accumulation curves. We found that main causes are (1) the phase lag between the viral reproduction process and a belayed immune response, (2) the direct viral damages and massive collateral damages which are mainly caused by belated immune responses, and (3) further tissue damages triggered by accumulated wastes in lungs. We deduced from those causes that the key strategies for preventing lung damages include avoiding direct lung infection, altering host-virus interactions, promoting immune responses, diluting virus concentrations in lung tissues by promoting viral migration to the rest of the body, maintaining waste removal balance, protecting heart function and renal function, avoiding other infections, reducing allergic reactions and other inflammation, etc. We finally discussed how to use dietary, medical, emotional, lifestyle, environmental, mechanical factors, etc. to alter disease outcomes. We show why true benefits of those factors cannot be determined by randomized controlled trials, and why the multiple-factor optimization approach can be highly effective by examining organ usable capacity in the cause of death. This treatment protocol using water, air, salt, sound, temperature, emotion, exercise, etc. can be the most powerful cures for viral and non-viral lung infections because they do not depend on molecular specificity and are freely available to anyone.