Dehydration Treatment
Part of First Aid
Oral rehydration therapy is the single most important medical intervention in a survival scenario — it has saved more lives than any antibiotic ever produced.
Dehydration kills faster than starvation. A person can survive weeks without food but only 3-5 days without water — and far less if they are losing fluids through diarrhea, vomiting, fever, burns, or heavy exertion in heat. The World Health Organization estimates that oral rehydration solution (ORS) has saved over 50 million lives since the 1970s. It is simple to make, requires only water, salt, and sugar, and it works.
Recognizing Dehydration
Catching dehydration early is critical. By the time severe symptoms appear, the patient may be too far gone for oral treatment alone.
| Sign | Mild (3-5% fluid loss) | Moderate (6-9% fluid loss) | Severe (10%+ fluid loss) |
|---|---|---|---|
| Thirst | Present | Intense | May be absent (too weak) |
| Mouth/lips | Slightly dry | Very dry, cracked | Parched, no saliva |
| Skin turgor (pinch test) | Normal | Slow return (2-3 sec) | “Tenting” — stays pinched |
| Eyes | Normal | Slightly sunken | Deeply sunken |
| Urine | Dark yellow, reduced | Very dark, scant | None for 6+ hours |
| Pulse | Normal | Rapid | Rapid and weak |
| Mental state | Normal | Irritable, restless | Lethargic, confused |
| Blood pressure | Normal | Low-normal | Low (shock imminent) |
The Skin Turgor Test
Pinch the skin on the back of the hand between two fingers, hold for 2 seconds, and release. In a well-hydrated person, the skin snaps back immediately. In moderate dehydration, it takes 2-3 seconds. In severe dehydration, the skin stays “tented” — it holds the pinched shape for several seconds or longer. This test is less reliable in elderly patients (skin loses elasticity with age) and in obese patients.
Oral Rehydration Solution (ORS)
This is the core treatment. ORS works because the gut absorbs water most efficiently when specific ratios of glucose and sodium are present — glucose and sodium share a co-transport mechanism in the intestinal wall, pulling water with them.
WHO Standard Formula
For 1 liter of clean (boiled and cooled) water:
- Salt (sodium chloride): 3 grams (roughly half a level teaspoon — about 6 pinches between thumb and first two fingers)
- Sugar: 18 grams (roughly 4 level teaspoons or 1 heaping tablespoon)
Stir until fully dissolved.
Warning
Getting the ratio right matters. Too much salt causes hypernatremia (excess sodium), which worsens dehydration and can cause seizures. Too much sugar causes osmotic diarrhea, pulling water INTO the gut and making things worse. If in doubt, err on the side of slightly less salt rather than more.
Alternative Recipes
When exact measurements are difficult, these alternatives provide acceptable rehydration:
The “pinch and scoop” method:
- 1 liter boiled water
- A three-finger pinch of salt
- A fistful (small handful) of sugar
- This is less precise but field-tested by aid organizations worldwide
Cereal-based ORS (more effective for diarrhea):
- Cook 50 grams of rice (or other starch: wheat, maize, potato) in 1 liter of water until soft
- Strain, keeping the starchy water
- Add half a teaspoon of salt to the starchy liquid
- The complex carbohydrates in the starch provide slow-release glucose, which is absorbed more efficiently than simple sugar and reduces stool output
Coconut water (if available):
- Natural coconut water contains electrolytes in roughly the right proportions
- Add a small pinch of salt (coconut water is slightly low in sodium)
- Use fresh — fermented coconut water loses its electrolyte balance
Administration
How you give fluid is as important as what fluid you give.
Dosing Guidelines
| Patient | Amount per dose | Frequency | Daily target |
|---|---|---|---|
| Adult (mild dehydration) | 200-400 ml | After each loose stool | 2-3 liters |
| Adult (moderate dehydration) | 200-400 ml | Every 15-20 minutes | 3-4 liters |
| Child (1-5 years) | 50-100 ml | After each loose stool | 500-1000 ml |
| Child (moderate dehydration) | 50-100 ml | Every 15-20 minutes | 1-1.5 liters |
| Infant (under 1 year) | 30-50 ml | After each loose stool | By weight — consult below |
Infant dosing by weight: 75 ml per kilogram of body weight over the first 4 hours. A 6 kg infant needs roughly 450 ml in the first 4 hours, given in small sips or via a spoon.
Technique
- Sip, don’t gulp. Large volumes trigger vomiting, especially in patients who are already nauseated
- Use a spoon for children. One teaspoon (5 ml) every 1-2 minutes. This is tedious but prevents vomiting
- If the patient vomits, wait 10 minutes, then restart with smaller, more frequent sips
- Continue breastfeeding infants in addition to ORS — breast milk provides both fluid and nutrition
- Do not stop giving ORS because the patient is still having diarrhea. The goal is to replace what is being lost, not to stop the diarrhea
When ORS Is Not Enough
Oral rehydration has limits. Recognize when a patient needs more than you can provide.
Signs that oral rehydration is failing:
- Patient cannot keep any fluid down despite small, frequent sips
- Urine output remains absent after 6 hours of treatment
- Mental state deteriorates — confusion, extreme lethargy, unresponsiveness
- Skin turgor does not improve after 4 hours of treatment
- Pulse remains rapid and weak
In a modern hospital, these patients would receive intravenous fluids. Without IV access, your options are limited:
Rectal fluid administration (proctoclysis): A last-resort technique used by field medics when patients cannot drink. The rectum absorbs water and electrolytes efficiently.
- Prepare standard ORS, cooled to body temperature
- Use any flexible tubing available — rubber tubing, cleaned garden hose section, even a hollowed reed in extreme cases
- Lubricate the tube end with any available fat, oil, or wet soap
- Insert 5-10 cm into the rectum
- Slowly introduce fluid — 100-200 ml at a time, over 15-20 minutes
- Allow 30 minutes between doses
- Target 500-1000 ml per hour until signs of hydration improve
This technique is not comfortable, not dignified, and not ideal. But it has saved lives when the only alternative was death.
Electrolyte Considerations
Dehydration is not just water loss — it is electrolyte loss. The four critical electrolytes:
| Electrolyte | Lost Through | Deficiency Signs | Natural Sources |
|---|---|---|---|
| Sodium | Sweat, diarrhea, vomiting | Confusion, muscle cramps, headache | Salt, seaweed, celery |
| Potassium | Diarrhea, vomiting | Muscle weakness, irregular heartbeat, fatigue | Bananas, potatoes, coconut water, leafy greens |
| Chloride | Sweat, vomiting | Usually paired with sodium loss | Table salt (NaCl), seawater (diluted) |
| Bicarbonate | Diarrhea (severe) | Rapid breathing, lethargy | Wood ash dissolved in water (use cautiously) |
Adding Potassium
Standard ORS does not contain much potassium. For patients with severe or prolonged diarrhea, potassium replacement is important.
- Mash half a ripe banana into the ORS
- Give boiled potato water (the water potatoes were cooked in) as a supplement
- Coconut water is naturally rich in potassium
- Offer orange or citrus juice diluted 1:1 with water between ORS doses
Prevention
The best treatment for dehydration is never getting dehydrated.
Daily Water Requirements
| Condition | Liters/day |
|---|---|
| Resting in shade, temperate climate | 2-3 |
| Light activity, temperate climate | 3-4 |
| Heavy labor, temperate climate | 4-6 |
| Any activity, hot climate (30°C+) | 5-8 |
| Fever (per degree above 37°C) | Add 0.5 |
| Diarrhea or vomiting | Add 1-2 per episode |
Monitoring Hydration
The simplest hydration monitor: urine color.
- Pale yellow to clear: Well hydrated
- Dark yellow: Mildly dehydrated — drink more
- Amber or brown: Significantly dehydrated — begin active rehydration
- No urine for 6+ hours: Emergency — begin ORS immediately
Making ORS in Bulk
When treating multiple patients (disease outbreak, group heat exhaustion):
| Batch size | Water | Salt | Sugar |
|---|---|---|---|
| 1 liter | 1 L boiled | 3 g (½ tsp) | 18 g (4 tsp) |
| 5 liters | 5 L boiled | 15 g (2½ tsp) | 90 g (20 tsp / ~6 tbsp) |
| 10 liters | 10 L boiled | 30 g (5 tsp) | 180 g (40 tsp / ~12 tbsp) |
Prepare fresh batches every 24 hours. ORS left at room temperature grows bacteria after one day. In hot climates, replace every 12 hours.
Key Takeaways
- ORS is 1 liter boiled water + half a teaspoon salt + 4 teaspoons sugar — getting the ratio right matters more than the exact amounts
- Give small, frequent sips (not gulps) to prevent vomiting; use a spoon for children
- The skin pinch test on the back of the hand is the fastest field assessment for dehydration severity
- Cereal-based ORS (rice water + salt) is more effective than sugar-based ORS for diarrheal dehydration
- If a patient cannot keep oral fluids down, rectal fluid administration is a viable last-resort technique that absorbs water efficiently