Dehydration

Dehydration may occur when the body loses too much fluid or when fluid intake is too low. Common causes of excess loss include diarrhoea, vomiting, heavy sweating, fever, excessive alcohol intake, certain medications (such as diuretics), and uncontrolled diabetes.³,⁴ In South Africa, hot weather and outdoor labour-intensive activities significantly increase fluid loss.⁸

Some people are at higher risk — particularly babies, young children, older adults, and individuals with chronic illnesses such as kidney disease or diabetes.¹ ³

Mild to Moderate Dehydration

Adults & Children

Symptoms include thirst, dry mouth, dizziness (especially on standing), headache, tiredness, darker urine, urinating less often, and in children, sunken eyes. ³,⁴

Babies and Young Children

Warning signs include fewer wet nappies, a dry or sticky mouth, no tears when crying, sunken eyes, sunken fontanelle, irritability, or unusual sleepiness.¹,³

Severe Dehydration

Symptoms can include extreme thirst, very little or no urination, rapid heartbeat, low blood pressure, confusion, cold extremities, pale or blotchy skin, and sunken eyes.⁵ Severe dehydration is life-threatening and requires urgent medical care.⁵

Doctors may diagnose dehydration through medical history, physical examination, testing how concentrated the urine is, or blood tests (for electrolytes and kidney function). ²

The main treatment is replacing lost fluids and electrolytes.¹ For mild dehydration, increased water and other fluid intake often suffice.⁵ When dehydration is linked to vomiting, diarrhoea, or heavy sweating, oral rehydration solutions (ORS) are recommended to replace fluid, salts, and minerals.²,⁴ Severe dehydration requires hospital care, including intravenous (IV) fluids.²

Drink fluids regularly throughout the day — do not wait until feeling very thirsty.¹ Drink more during hot weather, illness, or exercise.¹ ² Include foods with a high water content (fruits, vegetables, soups), and avoid prolonged sun exposure.⁸

Infants, young children, and older adults need extra monitoring because they may not recognise or communicate thirst.³

South African health authorities emphasise staying in the shade, carrying water when outdoors, and offering frequent small amounts of fluid to vulnerable individuals.⁸

Dehydration can happen to anyone, but it is especially dangerous for infants, children, older adults, and people with chronic illnesses.¹,³ Early symptoms include thirst, dark urine, tiredness, dizziness, and reduced urination.³ Severe dehydration is a medical emergency.⁵ Prevention includes regular fluid intake, using ORS when needed, and extra care during hot South African weather or illness.¹,²,⁸

This brochure is for educational purposes only and is not intended to provide a diagnosis or treatment or replace the advice of your doctor, pharmacist, primary health care nurse or other health care provider. You are advised to discuss any questions or concerns you have with your health care provider.