Mammary congestion is mainly a painful syndrome, principally related to diffuse edema of the gland, the radiological signs of which are described in this report. Excellent validity can be obtained by a trained observer of these signs. In contrast, however, thermographic signs are of less value, probably due to the presence of a more or less abundant superficial edema. This interferes with thermal propagation towards the skin covering, and could be the cause of the superficial hypothermia which is recorded in one third of patients with definite clinical congestion. Hormonal disturbances are observed frequently enough in this syndrome for them to be considered responsible for a large proportion of the congestive and edemaotus phenomena. Observation of these signs enables a choice of therapy to be made, but this is not discussed in this report.