Preeclampsia is a pregnancy complication characterized by the presence of hypertension and renal dysfunction. Preeclampsia leads to heterogeneous disorders, which ultimately has an adverse effect on the health of the mother and fetus. The most common cause of illness and death among mothers and perinatals, preeclampsia affects 7–18% of pregnancies. Furthermore, problems resulting from preeclampsia accounted for almost one-third of all maternal fatalities connected to pregnancy. Preeclampsia's elevated arterial pressure can cause placental abruption, miscarriage, early delivery, low birth weight, and even the mother's or fetus's death. The relative risk of fetal death in early Preeclampsia is 5.8%, in late Preeclampsia - 2.0%. After delivery, patients with Preeclampsia noted hypertension (39% for 3 months), proteinuria (20% for a year). At the same time, there is an increased risk of diabetes mellitus. The most severe clinical variants of the course of Preeclampsia are associated with maladaptation of the immune system and impaired placentation. They are characterized by such manifestations as early activation of the sympathoadrenal system, an increase in the level of markers of endothelial dysfunction, insufficient invasion of the trophoblast and incomplete transformation of the spiral uterine arteries. This article examines the scientific information about Preeclampsia in order to clarify the facts.