Abnormal circulating unsaturated fatty acid concentration Abnormal circulating eicosanoid concentration UMLS:C4072901 Abnormality of icosanoid metabolism Any deviation from the normal concentration in the blood circulation of an icosanoid (also known as eicosanoids). These are signaling molecules derived from oxidation of 20-carbon fatty acids. Most are produced from arachidonic acid, a 20-carbon polyunsaturated fatty acid (5,8,11,14-eicosatetraenoic acid). The icosanoids include the prostaglandins, prostacyclins, thromboxanes, leukotrienes, and epoxyeicosatrienoic acids. Icosanoids have various roles in processes that regulate inflammation, fever, blood pressure, blood clotting, immune system function, reproductive processes and tissue growth, and the sleep/wake cycle.