Clinical neurochemistry is the field of neurological biochemistry which relates biochemical phenomena to clinical symptomatic manifestations in humans. While neurochemistry is mostly associated with the effects of neurotransmitters and similarly-functioning chemicals on neurons themselves, clinical neurochemistry relates these phenomena to system-wide symptoms. Clinical neurochemistry is related to neurogenesis, neuromodulation, neuroplasticity, neuroendocrinology, and neuroimmunology in the context of associating neurological findings at both lower and higher level organismal functions.