A changed level of sodium atom in the blood.
http://purl.obolibrary.org/obo/UPHENO_0051690
http://purl.obolibrary.org/obo/MP_0001776
http://purl.obolibrary.org/obo/UPHENO_0046356
http://purl.obolibrary.org/obo/UPHENO_0076286