De-Hide-Ration

A few weeks ago, the government warned the citizens to brace themselves for one of the hottest summers on record. Most people dismissed it. But now many are ‘facing the heat’ with summer headaches, sudden nausea, fatigue, dehydration despite drinking water all day, and, surprisingly, even colds during peak heat. The body feels confused — drained one moment and overheated the next. According to Dr Manjusha Agarwal, Consultant-Internal Medicine at Gleneagles Hospital, hidden dehydration refers to a “mild or unnoticed fluid deficiency where the body lacks adequate water even before obvious symptoms like extreme thirst appear.” She explains that people who spend long hours indoors in air-conditioned environments, remain occupied at work, or fail to realise how much fluid they are losing through sweating, caffeine intake, or physical activity.

The truth is that hydration goes beyond just drinking water and popping vitamins. Excessive sweating strips the body of essential minerals and electrolytes, leaving us feeling weak and dizzy even after multiple bottles of water. Air conditioners, irregular eating habits, caffeine intake, and constant exposure to heat only worsen the situation.

SIP SIP DRIP DRIP

It takes more than just drinking more water to overcome this situation. Making a few lifestyle changes and smart eating helps the body cope better with extreme temperatures. “Dehydration can reduce energy levels and concentration while also causing headaches, dizziness, constipation, dry skin, and digestive discomfort,” says Dr Agarwal. “It may also affect mood, leading to irritability, fatigue, anxiety, or difficulty focusing.” A good start would be by including electrolyte-rich fluids, seasonal fruits with high water content, lighter meals and reducing direct sun exposure by wearing a scarf during peak afternoon hours.

PEEK-A-BOO

An overlooked factor is overcooling the body. Constant switching between scorching outdoor heat and freezing air-conditioned spaces can stress the immune system, leading to throat irritation, headaches, and fatigue. Hidden dehydration does not always announce itself dramatically. It leaves you feeling “off” while you continue believing you are doing everything right. “Excessive caffeine and alcohol intake can contribute to dehydration because they increase fluid loss,” says Dr Agarwal.

Alcohol also affects the body’s ability to retain water and may worsen dehydration, especially during hot weather or after physical activity. Very high-protein diets and inadequate intake of fruits and vegetables can also affect hydration levels. Hydration today is not just about drinking litres of water — it is about maintaining the body’s electrolyte balance as well.

“Electrolytes such as sodium, potassium, and magnesium help regulate fluid balance, nerve activity, and muscle function. When these minerals are lost through sweating or illness, the body struggles to use and retain water properly. Diets high in salty, processed, sugary, or spicy foods can increase fluid loss and worsen dehydration,” says Dr Aggarwal. “Very high-protein diets, excessive caffeine intake, and low consumption of fruits and vegetables may also reduce overall hydration levels.''

Children Most Vulnerable

Hidden dehydration is extremely common among children because many remain busy playing outdoors and fail to recognise their own thirst signals. Dr Sanju Sidaraddi, Consultant-Paediatrician and Neonatologist at Motherhood Hospitals, says, “Children can still become dehydrated even if they drink water regularly, especially if they are sweating excessively, playing outdoors, having fever, vomiting, diarrhoea, or consuming too many sugary drinks instead of balanced fluids.”

Even young adults who appear healthy are increasingly reporting dehydration-related symptoms due to long commutes, poor eating habits, excessive screen time, and constant exposure to harsh weather conditions. One of the biggest concerns is that children often fail to recognise or communicate thirst properly. Many children continue playing outdoors for hours without pausing to hydrate adequately.

According to Dr Sidaraddi, fever, vomiting, diarrhoea, excessive sweating, and sugary beverages can all contribute to fluid imbalance. “Children may consume juices, soft drinks, or flavoured beverages thinking they are hydrating themselves, but many of these drinks contain excess sugar that may actually worsen dehydration,” he adds.

FOODS THAT HELP

Coconut water, lemon water with a pinch of salt, and buttermilk can help replenish lost nutrients. Seasonal fruits such as watermelon, muskmelon, oranges, cucumber, and berries also provide natural hydration while supplying vitamins and minerals. Electrolyte sachets and wellness hacks have become increasingly popular, but experts caution that balance is key. Too much sodium intake can also create health complications, especially for individuals with blood pressure concerns or underlying medical conditions. One of the biggest misconceptions is that thirst is the only warning sign.

Telltale Signs

By the time thirst kicks in, the body may already be mildly dehydrated. Persistent headaches, dry lips, brain fog, muscle cramps, unusual fatigue, darker urine, and sudden sugar cravings. Parents should also pay attention to subtle behavioural and physical changes. “Dehydration in children can lead to tiredness, poor concentration, headaches, constipation, dry skin, irritability, mood changes, and low energy levels,” says Dr Sidaraddi. “Some children may become cranky, unusually quiet, or less active during hot weather.”

Extreme heat and dehydration can worsen skin sensitivity, dullness, acne flare-ups, and premature dryness. Hair fall and brittle nails also become more common during intense summer heat. “I carry a protein bar in my bag and have avoided coffee or any sort of drinks that could dehydrate me,’’ says Irvin D’costa, a gym trainer from Mumbai.

As temperatures continue to rise globally, understanding hydration is becoming more important than ever. Because hidden dehydration does not always arrive dramatically. It hides behind everyday headaches, unexplained fatigue, or that “off” feeling — even when you believe you are doing everything right.