Alcohol-related illnesses have increased in under-18s in recent years
Nearly 25% of 16 to 64-year-olds in the South West - about 750,000 people - are classed as "hazardous" drinkers, according to new figures.
The statistics, in a report by the South West Public Health Observatory (SWPHO), also reveal more than 100,000 are dependent on alcohol.
The report recommends efforts should be focussed in deprived areas and for groups identified as the most at risk.
These include education for under-18s and more support for chronic drinkers.
The report says more than 500 people aged under 18 are admitted to hospital specifically due to alcohol each year in the South West, with boys and girls equally likely to be admitted.
It also says drink-driving is estimated to account for more than 168 serious injuries and about 50 road deaths in the region each year.
Hazardous drinkers are categorised by the World Health Organisation as people who drink above recognised sensible levels but are not yet experiencing harm.
The SWPHO report says hazardous drinking can double men's risk of liver disease, raised blood pressure, some cancers and violent death.
In women, it increases the risk of liver disease and breast cancer.
According to the 1992 government White Paper, sensible drinking limits were defined as a weekly alcohol consumption of less than 21 units for men and less than 14 units for women.
Health authorities and agencies in the region, which covers Devon, Cornwall, Isles of Scilly, Avon, Somerset, Gloucestershire, Dorset and Wiltshire, are now working together to develop a joint strategy to support those whose drinking is out of control.
The South West Public Health Observatory was created in 2005. Its key tasks include monitoring health and disease trends.