Background Alcohol hangover (AH) contributes to alcohol‐related economic costs [1]. Estimates of AH frequency and severity in previous reports are often limited, employing a one‐off survey involving long recall periods up to 12 months [2–6]. The study examined AH frequency and severity using a weekly online survey for ≥6 months.

Approach Data was collected on 49 participants (19 males; age 38±10 years). Survey questions were related to AH occurrence and factors associated with the worst AH of the week, including the amount of alcohol consumed and AH severity. Pearson correlation was used to investigate the relationship between frequencies of AH and weekly alcohol consumption. AH severity was calculated as the sum of HSS‐5 [7] item scores (total ≤10 – classified as mild; 11‐25 – moderate; 16‐25 – severe).

Outcomes From a total of n=1881 weekly responses, n=604 hangovers were recorded. Participants reported between 0 and 41 AHs over 52 and 35 weeks, respectively. No correlation was observed between AH frequency and weekly alcohol consumption (r=0.164, P=0.259). Five hundred and three AHs were identified as the worst (35% mild, 38% moderate, 27% severe). No severe AHs were reported when <4 standard drinks were consumed.

Conclusions Using a regular short recall weekly survey, AH frequency was higher than previously reported. These findings indicate that AH‐related costs to society may have been previously underestimated.