ORS (Oral Rehydration Salts): Uses, Mixing and Safety

5 min read · Medicines · By the Asthra Health Care team

What ORS is used for

Oral rehydration salts, or ORS, is a powder of glucose and salts, including sodium and potassium, that is mixed with clean water. It is the main treatment for dehydration caused by diarrhoea, especially in children. The World Health Organization and Indian health programmes recommend the low-osmolarity formula found in most standard packets today.

Diarrhoea is common during the Indian summer and monsoon, when water and food are easily contaminated. ORS is also useful for dehydration from vomiting, fever, heat exhaustion and heavy sweating during outdoor work. It does not stop diarrhoea by itself, but it prevents the dangerous loss of water and salts that makes people seriously ill.

• Diarrhoea in children and adults, including cholera and food poisoning
• Dehydration from vomiting or fever
• Heat exhaustion and heavy sweating
• Mild dehydration during dengue or other viral fevers, alongside medical care

How ORS works

The gut absorbs sodium more efficiently when glucose is present. ORS uses this natural process: the glucose helps pull sodium across the gut wall, and water follows the salts into the body. This works even during diarrhoea, when plain water alone is not absorbed well.

The balance of salt and sugar is carefully set. Too much sugar, as in soft drinks and packaged fruit juices, can draw water into the gut and make diarrhoea worse. Too much salt can also be harmful. This is why a proper ORS packet, mixed exactly as printed, is better than guessing.

Side effects and safety

When prepared correctly, ORS is very safe. Some people, especially children, may vomit if they drink too fast. Giving small, frequent sips with a spoon or cup usually solves this. A salty taste is normal. If a child vomits, wait a few minutes and then start again more slowly; most children keep ORS down when it is given patiently in small amounts.

Problems happen mainly when ORS is mixed wrongly. Using too little water makes the solution too salty, which can be dangerous, especially for babies. Using too much water makes it weak and less useful. Mixed ORS should be used within the time printed on the packet, usually one day, and then thrown away.

Who should take extra care with ORS

People with kidney disease, heart failure or conditions that need a restricted salt or fluid intake should ask a doctor before using ORS, as extra salts and fluid may not suit them. People with diabetes can usually use standard ORS during diarrhoea, but should check blood sugar more often and talk to their doctor.

For babies, keep breastfeeding alongside ORS. Infants and young children, elderly people and pregnant women become dehydrated more quickly, so they need closer watching. Doctors also give zinc tablets or syrup to children with diarrhoea, as advised under national guidelines, but this is a medical decision.

Interactions and what not to mix

ORS does not have important medicine interactions, but it should be mixed only with clean water. Do not add sugar, salt, juice, milk or glucose powder to the packet, as this upsets the balance. Do not replace ORS with sports drinks, soft drinks or energy drinks, which contain too much sugar and too little salt for diarrhoea.

Some flavoured ready-to-drink products look like ORS but are not made to the medical formula. Check that the packet says it follows the WHO-recommended formula. Anti-diarrhoea tablets such as loperamide should not be given to children unless a doctor advises, and ORS remains the main treatment.

Practical tips for using ORS

Wash your hands, use boiled and cooled or safe drinking water, and add the whole packet to the exact volume printed on it. Stir well until it dissolves. Offer small sips often, and give more after each loose stool or vomit. Follow the packet or your pharmacist's advice on how much to give by age.

Continue normal feeding. Soft foods like rice with dal, curd rice, idli, khichdi and bananas are fine. Keep a few ORS packets at home, especially before summer and monsoon. Prevent diarrhoea with safe drinking water, handwashing with soap and fresh, hot food.

• Use the exact amount of water printed on the packet
• Give small sips often rather than large gulps
• Throw away leftover solution after the time on the packet
• Keep breastfeeding babies throughout

When to talk to your doctor about ORS

Take the person to a doctor if diarrhoea lasts more than two days, there is blood in the stool, a high fever, repeated vomiting that stops them keeping ORS down, or signs of dehydration that are not improving. Babies and elderly people should be seen early. Ask your doctor or pharmacist if you are unsure how to use ORS.

This article is general health information, not medical advice. Do not start, stop or combine medicines on your own — always follow your doctor's prescription and ask your pharmacist if unsure.