Toxemia is similar to virtually all human hypertension, where vasospasm and increased peripheral resistance is the cause of the hypertension. The contraction in extracellular volume in preeclampsia is similar to what is seen in essential hypertension.1-2 Diuretics have an antihypertensive effect in preeclampsia as in other hypertensive states. In the rare instance where severe hemoconcentration occurs with preeclampsia, one might want to begin therapy with a vasodilator, but, in most instances, diuretics are valuable additions to the therapy.