hyperviscosity syndrome
[ˌhaipə:visˈkɔsiti ˈsindrəum]
Hyperviscosity syndrome is a group of symptoms triggered by increase in the viscosity of the blood. Symptoms of high blood viscosity include spontaneous bleeding from mucous membranes, visual disturbances due to retinopathy, and neurologic symptoms ranging from headache and vertigo to seizures and coma.