This thesis aims to investigate the complex symptomology of migraine as a cyclic neurological disorder. The literature on migraine is primarily focused on the pathophysiological underpinnings of the migraine headache and pharmacological interventions. However, some migraine research has highlighted that the migraine headache merely constitutes a singular phase of the condition that is preceded by the migraine prodrome and followed by the migraine postdrome. Rather than being characterised by pain, the prodrome and postdrome phases are distinguished by changes in behavioural, affective, and cognitive states. This is the first theoretical framework of this thesis. The second framework used in this thesis is the circadian framework, which examines the daily rhythmic fluctuations in physiology and behaviour. These two frameworks, although distinct, have considerable anatomical and symptomatic overlap with both implicating sleep, eating behaviours, activity, and thermoregulation. As such, the impact of migraine goes beyond the severity of pain and reflects comprehensive disability. This thesis examines circadian behaviours and psychological factors in individuals with migraine compared to non-migraine individuals, within migraine frequency groups and across the phases of migraine. To establish the level of cognitive impairment in individuals with migraine, Chapter Two of this thesis reviews the current literature on neuropsychological functioning in adult migraineurs published over the last two decades. Chapter Three investigates cross-sectional associations of sleep and eating factors in migraine and examines the differences in sleep and eating behaviours between individuals with and without migraine. Chapter Four subjectively examines migraine using semi-structured interviews and highlights the dimensional lived experience of migraine that impairs the individual physically, psychologically and socially. Chapter Five investigates the longitudinal associations of sleep (subjective and objective), self-reported mood, stress, and fatigue, self-reported changes in perceived temperature and appetite, activity (step count) and heart rate variables in affecting migraine onset, characteristics, and phases. This chapter further investigates associations of neuropsychological functioning and phase structured by testing session. Chapter Six examines participants’ experiences participating in the longitudinal study outlined in Chapter Five to enable insight and adaptation for future research using similar designs. The findings of this thesis highlight the need for migraine to be recognised as a cyclic disorder that has physical, behavioural, psychological, and social implications in both research and practice but also at a population level where it is frequently misunderstood. The findings warrant further investigation into the role of circadian rhythms in migraine pathophysiology and the overlap in migraine symptoms and circadian behaviours. Future research is needed to clearly establish the psychological, behavioural, and temporal characteristics of each of the migraine phases.