Signs of Dehydration in Adults and Kids: A Parent Guide

Busy parents are often the last people in the house to drink anything. You fill the kids’ water bottles, pack the squash for the park, and then realise at 4pm that all you have had today is two cold cups of tea. A dull headache, feeling irritable, struggling to concentrate on the email in front of you: these can all be signs of dehydration. This post is not another “drink X glasses a day” lecture. It is about spotting the signs in yourself and your kids, and building simple habits so it does not keep happening.

If you want to know about daily amounts, I have covered that separately in how much water should I drink. This one is about noticing.

Signs of dehydration in adults

The NHS page on dehydration lists common symptoms in adults and children, including:

• Feeling thirsty.
• A headache.
• Dark yellow, strong-smelling pee.
• Peeing less often than usual.
• Feeling dizzy or lightheaded.
• Feeling tired.
• A dry mouth, lips and tongue.
• Sunken eyes.

In real life, the early version for most parents is a mid-afternoon slump, a mild headache and craving something sugary. That does not always mean dehydration, but it is a good prompt to have a drink and see if you feel better.

The quick pee check

The simplest daily check is the colour of your pee. The NHS says your pee should be a pale colour over the day if you are drinking enough, and dark yellow, strong-smelling pee is a sign of dehydration. Some vitamins and foods can change the colour, so look at the general pattern rather than one visit.

Signs of dehydration in babies and children

Children can get dehydrated more quickly than adults, especially when they are ill with diarrhoea or vomiting, have a fever or have been running around on a hot day. The NHS lists extra signs to look out for in babies and young children, including:

• A sunken soft spot (fontanelle) on top of a baby’s head.
• Few or no tears when crying.
• Fewer wet nappies than usual.
• Being drowsy or irritable.

The NHS advises asking for an urgent GP appointment or contacting 111 if a child is drowsy, has fewer wet nappies or is peeing less than normal, or has few or no tears when crying. It says to call 111 for advice about a child under 5. Call 999 if they have signs such as blue, grey, pale or blotchy skin or lips, cold skin, difficulty breathing or are sleepier than normal and hard to wake. If you are not sure, it is always better to get them checked.

For day-to-day drinks for kids, Healthier Together has useful guidance on healthy drinking for children, and my post on how much water children should drink gives practical tips for the school day.

When adults need medical help

Most mild dehydration in healthy adults gets better by drinking more. If you are being sick or have diarrhoea, the NHS says a pharmacist can recommend oral rehydration solutions to replace lost sugar, salts and minerals. It advises an urgent GP appointment or contacting 111 if you have unusual tiredness, dizziness on standing that does not go away, dark yellow pee or are peeing less than normal, or a fast heartbeat or fast breathing. Call 999 for serious signs such as confusion, difficulty breathing, cold or blotchy skin, or being very sleepy and hard to wake.

If you have diabetes, kidney or heart problems, or take medicines that affect your fluids, check with your GP about what is right for you.

Exercise and dehydration

When you train, you lose fluid through sweat, even indoors and even in winter. Here is what I suggest to people who come to my classes:

1. Start topped up. Have a drink in the hour or two before you exercise, not a huge amount at the door.
2. Bring a bottle and take small sips in the rest breaks.
3. Check after. If you feel dizzy, headachy or very tired after a session, drink, eat something and take note for next time.
4. Be extra careful in heat or if you have been ill recently. My post on exercising in hot weather covers this in more detail.
5. Do not overdo it. Drinking very large amounts in a short time is not a good idea either. Sip steadily.

A simple hydration habit plan for busy families

The problem is rarely knowledge. It is remembering. These habits help:

• Anchor drinks to things you already do: a glass of water when you put the kettle on, after the school drop-off, when you sit down for lunch and when you start cooking dinner.
• Keep your own bottle next to the kids’ bottles, so when you fill theirs, you fill yours.
• Use food. Soups, fruit, yoghurt and veg all contribute fluid. The NHS water, drinks and your health page notes that lower-sugar drinks, including tea and coffee, count towards your daily intake too.
• Make it visible for kids. A sticker chart for younger ones, or a race to finish their bottle before pick-up.
• Watch the afternoon slump. Before reaching for biscuits, try a glass of water and a short walk. See if it helps.

Where a bootcamp class fits

A class is a good weekly reminder to look after yourself, including drinking enough. In my classes we have proper rest breaks, every exercise has an easier and harder option, and I will always remind people to bring a bottle. If your main problem is low energy in the afternoon, the SYP Recharge class is designed for exactly that.

FAQs

What are the first signs of dehydration?

Often thirst, darker pee, a dry mouth, tiredness and sometimes a headache. Having a drink and checking if you feel better is a sensible first step.

Can dehydration cause headaches?

It can be one cause, though headaches have many causes. If you get frequent or severe headaches, see your GP.

Does tea or coffee dehydrate you?

The NHS says lower-sugar drinks, including tea and coffee, count towards your fluid intake. Just be aware of caffeine late in the day if sleep is an issue.

How quickly can you rehydrate?

Mild dehydration often improves quite quickly once you drink. If symptoms do not improve, or you cannot keep fluids down, contact 111 or your GP.

Book your first class

Want more energy and a weekly routine that puts you first for once? SYP Bootcamp runs 45-minute small-group classes in an indoor church hall in Archway N19, maximum 10 people, £15 a class. Bring a water bottle and I will do the rest. Book your £15 class or call or WhatsApp me on 07301 512215. If you prefer coaching with nutrition and habit support between sessions, take a look at my online coaching.

About the author

Artem Olekhnovych is a personal trainer in Archway and the founder of SYP Fitness and SYP Bootcamp. He has coached clients in Archway, Highgate and across North London for over 10 years, and runs small-group bootcamp classes for busy mums and dads. Read reviews from his 1-1 clients.