Keep yourself hydrated on every hike
Keeping yourself hydrated during any hike is crucial as the exertion makes you susceptible to dehydration, which can make a hike less enjoyable and potentially dangerous. There are many reports of hikers needing to be rescued due to dehydration because they ran out of water. Sadly, some have not survived.
You can become dehydrated even during winter but your risks are increased dramatically during dry, hot conditions under the Aussie sun. The easiest way to keep yourself hydrated is to drink plenty of fluids before, during and after any adventure.
What is dehydration?
Dehydration occurs when you don’t have enough fluids in your body. If severe, dehydration can cause serious problems. If you suspect you are (or someone else is) dehydrated, stop, get out of the heat and re-hydrate. In severe cases, stop and seek medical attention. You are dehydrated if your body doesn’t have enough water to keep it working properly. It can happen when your body loses too much fluid from excessive sweating. If dehydration is not corrected by fluid intake, eventually urination stops, the kidneys fail, and the body can’t remove toxic waste products. In extreme cases, dehydration may result in death.
How to spot dehydration
Mild to moderate dehydration symptoms
- Thirst
- Dry or sticky mouth
- Headache
- Reduced urine output
- Darker yellow urine
- Fatigue or low energy
- Dizziness or lightheadedness
- Weakness
- Dry lips or skin
- Reduced concentration or slower thinking
Severe dehydration symptoms
- Very little or no urination
- Dark yellow or brown urine
- Rapid heartbeat
- Rapid breathing
- Low blood pressure
- Sunken eyes
- Extreme fatigue or lethargy
- Confusion or altered mental state
- Collapse, delirium, or unconsciousness
- In severe cases, heat exhaustion or heat stroke
Test your skin: Using tow fingers grab a small amount of skin on the back of your hand. The best location to do this between your wrist and where your fingers start. Pull the skin up and let the skin go. The skin should spring back to normal position very quickly. If this takes more than a couple of seconds for the the skin to bounce back you might be dehydrated.
Check your urine: Urine colour and frequency can provide a useful rough guide to hydration status. Pale yellow urine generally suggests adequate hydration, while darker urine often indicates increasing dehydration. Very clear urine is not necessary and can indicate excessive fluid intake. If you are sweating heavily and not urinating for several hours, stop, rest, and drink fluids. Urine that is brown or tea-coloured requires immediate medical attention.
Tips to prevent dehydration
- Drink fluids regularly before, during, and after hiking
- Avoid alcohol before and during hikes
- Carry sufficient food and water, with water easily accessible
- Do not rely solely on thirst in hot or strenuous conditions
- Adjust pace and rest breaks in hot weather
- Wear appropriate clothing to reduce heat stress
- Increase fluid intake as sweat loss increases
Overhydration and hyponatremia
Overhydration, also known as hyponatremia, occurs when excessive fluid intake dilutes the sodium levels in the blood. Sodium is an essential electrolyte that helps regulate fluid balance, nerve function, and muscle contraction. When sodium levels drop too low, water can move into cells and cause them to swell, which can be dangerous.
Hyponatremia is uncommon, but it has been documented in hikers and endurance athletes, particularly during long or strenuous activity where large amounts of plain water are consumed without adequate electrolyte replacement. It is most likely to occur during prolonged exercise, in hot conditions, or when fluid intake greatly exceeds sweat and sodium losses.
The symptoms of hyponatremia can be similar to dehydration, which can lead some hikers to mistakenly drink more water and worsen the condition. Symptoms may include fatigue, headache, nausea, confusion, muscle cramps, and swelling of the hands or face. In severe cases, hyponatremia can lead to seizures, coma, or death.
Preventing overhydration
Preventing overhydration is about maintaining balance rather than following fixed drinking rules.
- Drink according to conditions, exertion, and sweat loss rather than forcing fluids
- Include electrolytes or salty foods on longer hikes or in hot conditions
- Avoid excessive intake of plain water without food or electrolytes
- Pay attention to how your body feels and adjust intake accordingly
For most hikers, dehydration remains a far more common risk than overhydration. Carrying enough water, drinking regularly, and replacing electrolytes when needed provides the safest approach to hydration on the trail.
Related articles
Overhydration and Hyponatremia
Recently became dehydrated while MTB. Scariest thing ever. Didn’t feel it coming and it just hit me. I was very ill.
It’s sneaky and occurs without you noticing. Save your own life!
It’s important to note that by the time you feel dehydrated, you are well past needing fluids. So it’s best to continually hydrate and to use electrolytes if it’s a long hike or hot day and you are drinking a lot.