The present invention provides a method of treating and preventing altitude sickness, comprising the steps of: obtaining a peptide, wherein the peptide is 7-20 adjacent amino acids in length and comprises an amino acid sequence having a hexamer TX1EX2X3E, wherein X1, X2 and X3 can be any natural or unnatural amino acid, and wherein the peptide does not have tumor necrosis factor receptor binding activity, and wherein the peptide is cyclized； and administering to a patient having the pulmonary form of altitude sickness or being at risk of developing the pulmonary form of altitude sickness an effective amount of the peptide.
