The most serious form of pneumonia is severe pneumonia, also known as toxic pneumonia, which is caused by various pathogens that lead to serious infections in the lungs, resulting in severe inflammatory toxic reactions throughout the body. Patients need to be admitted to the intensive care unit for resuscitation treatment. In addition, the seriousness of severe pneumonia lies in the seriousness of the clinical symptoms and complications. Patients can also be induced to develop severe respiratory failure, and patients mostly need to use ventilators to assist their respiratory treatment. Patients are prone to infectious shock and can suffer from secondary cardiac impairment, including myocarditis and heart failure in some patients. Patients can also cause damage to liver and kidney function, especially renal failure, which is manifested by low urine and elevated creatinine, and patients mostly need dialysis treatment, and a few patients eventually die clinically due to multiple organ failure.