Alcohol And Dehydration

How to manage dehydration due to excessive alcohol

Excess alcohol consumption leads to dehydration. The symptoms of mild to moderate dehydration include:

  • Dry mouth
  • Increased thirst
  • Headache
  • Lethargy (tiredness)

These symptoms are all commonly observed as a result of excess alcohol consumption.

The National Health and Medical Research Council (Australia) recommends that adult men and women drink no more than 4 standard drinks on any one drinking occasion. Above that number is considered excess and can increase the risk of health-related injury.

In Australia, a standard drink is any drink containing 10 grams of pure alcohol, and beverage labels are required to state the number of standard drinks.

Alcohol is a diuretic (a substance that increases urine output).

Research has shown that approximately 100 ml of additional urine output occurs for every 10g alcohol consumed.

Excessive alcohol consumption involving 6 to 10 standard drinks could therefore lead to a net fluid loss of 600 – 1000 ml or more and therefore significant dehydration.

Drinking non-alcoholic beverages (e.g. water, juice) during and soon after alcohol consumption may reduce the level of dehydration. However, drinking an oral rehydration solution such as Hydralyte offers some advantages:

  • Rehydration is likely to be more rapid
  • The retention of water and electrolytes is better
  • A person may experience better sleep (and therefore feel better afterwards) due to the lessened urge to urinate during the night

The Physiology of Alcohol-Induced Dehydration

Alcohol promotes urine production by inhibiting the release of a hormone (antidiuretic hormone, ADH or vasopressin) from the pituitary gland. In turn, reduced levels of ADH prevent the kidneys from conserving water and therefore increase urine production. The result is a net loss of fluid and electrolytes, and therefore dehydration.

Suggested Dosage

Take 400 ml of Hydralyte (slowly) after the drinking occasion and prior to going to bed.

Consult with your doctor or pharmacist if you intend to take Hydralyte for more than three days in a row.


Hydralyte contains approximately 0.8 mg/ml potassium. If you have kidney disease or are taking heart or blood pressure medicines – consult your doctor before using Hydralyte.
Hydralyte contains sodium. Refer to packaging for content. 


  1. Eggleton MG. 1942. The diuretic action of alcohol in man. Journal of Physiology 101: 172-191
  2. Strauss MB, Rosenbaum JD and Nelson WP. 1950. The effect of alcohol on the renal excretion of water and electrolyte. J Clinical Investigation. 29 (8): 1053-1058.
  3. Swift R and Davidson D. 1998. Alcohol Hangover Mechanisms and Mediators. Alcohol Health and Research World. 22 (1): 54-60.
  4. Wiese JG, Shlipak MG, Browner WS. 2000. The alcohol hangover. Annals of Internal Medicine: 132 (11): 897 - 902


Always read the label and use only as directed. If symptoms persist see your healthcare professional.