Hydration Guidelines for a Healthy Summer

Gulp, gulp. With the early onset of scorching heat, many people find themselves constantly drinking water. However, this seemingly harmless habit can actually be harmful to your health if not done properly. Elderly individuals, in particular, should sip water regularly, but those with underlying health conditions need to monitor and adjust their intake carefully. Here are 8 useful tips for staying hydrated safely during the summer.

■ No Need to Obsess Over “8 Glasses a Day”

The idea that you must drink eight glasses of water daily is still widely believed, but numerous studies have shown that this guideline doesn’t necessarily offer special health benefits. The recommended daily fluid intake (about 2.5 liters) doesn't have to come from water alone—foods and other beverages also contribute to hydration.

Professor Da-hye Son of the Department of Family Medicine at Gangnam Severance Hospital explained, “Koreans typically consume a lot of fruits and vegetables, which alone contribute over 1 liter of fluid intake daily.” She added, “There is no fixed amount of water that is universally ‘good’ for health—the ideal intake varies depending on dietary habits, body weight, and age.”

■ Don’t Gulp Down Water All at Once

Drinking a large amount of water in a short time can dilute the sodium levels in the body, leading to hyponatremia. This condition may cause headaches and nausea, and in severe cases, it can result in seizures or loss of consciousness. Extra caution is needed for older adults, individuals with neurological conditions, and infants under the age of two, as their ability to regulate fluids is reduced.

■ Consult a Doctor if You Have Underlying Health Conditions

For individuals with chronic illnesses, it is safest to follow a doctor’s guidance on fluid intake. Professor Son Da-hye cautioned, “In patients with heart failure, chronic kidney disease (especially those undergoing dialysis), or liver cirrhosis, excessive water intake can lead to serious complications such as ascites, pulmonary edema, or generalized swelling.” She emphasized the importance of extra caution for these groups.

■ Elderly Individuals Should Sip Water Regularly

As people age, kidney function declines and the brain’s thirst center becomes less responsive, making it harder for older adults to recognize when they’re dehydrated. Therefore, it’s important for them to consciously drink water throughout the day.
Professor Hyun-young Shin of the Department of Family Medicine at Seoul St. Mary’s Hospital, Catholic University, advised, “To avoid the risk of hyponatremia, it’s best to drink in small sips—less than 500ml at a time—and those with underlying conditions should consult their physician.”

■ Plain Water on an Empty Stomach in the Morning

Drinking water first thing in the morning helps replenish fluids lost during sleep and stimulates bowel movements, aiding digestion. While either plain water or barley tea can be beneficial, plain water is generally preferred since barley tea has a diuretic effect, which may lead to further fluid loss.

■ Follow the 30-Minute Rule Before and After Meals

Drinking water 30 minutes before a meal can help regulate appetite, while drinking it 30 minutes after a meal can aid digestion. It’s best to avoid drinking water during meals, as it can cause the stomach to bloat and dilute digestive enzymes, leading to discomfort and slower digestion.

■ Choose Bottled Water Over Purified Water

Purified water from water dispensers often passes through sterilizing filters that may also remove beneficial minerals. In contrast, natural bottled waters—such as deep-sea water, mineral spring water, or ionized water—tend to retain a variety of essential minerals. However, it is crucial to ensure that the water is clean and free from contamination.

■ Choose Pure Water Over Sparkling Water

While sparkling water contains no sugar or calories like soft drinks, it can erode tooth enamel and worsen bloating in individuals with irritable bowel syndrome (IBS). Many people drink sparkling water during dieting, but studies have shown it may increase levels of ghrelin—a hormone that stimulates hunger—which could actually lead to weight gain.