Tropical Diseases

Most stomach trouble in Koh Samui is mild traveller’s diarrhea. It usually settles within one to two days with rest and oral rehydration salts. See a doctor the same day if you notice blood in your stool, a fever above 39 C, severe belly pain, signs of dehydration, or symptoms lasting more than two days.

Food poisoning usually hits within one to six hours of a bad meal, with sudden vomiting and strong cramps, and passes in a day or two. Traveler’s diarrhea builds more slowly, one to three days after exposure, with loose stools and mild cramps, lasting two to four days. See a doctor for blood in stool, high fever, or dehydration.

After food poisoning, fluids come first: water, oral rehydration salts, and clear broth in small, frequent sips. Once vomiting stops, eat small amounts of plain rice, rice soup (khao tom), bananas, toast, or crackers. Wait a few days before spicy food, fried food, dairy, alcohol, and coffee. If fluids will not stay down, see a doctor.

Early dengue fever symptoms look like a bad flu: sudden high fever, severe headache, pain behind the eyes, and deep muscle and joint aches. The 3-day rule is simple: if your fever lasts more than three days, or any warning sign appears sooner, get a dengue blood test. The NS1 rapid test works from the first days of fever.

Do not take ibuprofen for a fever in Thailand until dengue has been ruled out. Dengue lowers your platelets, the blood cells that stop bleeding, and ibuprofen, aspirin, and other NSAIDs thin your blood further. Together they can cause serious bleeding. Take paracetamol only, and get a dengue test if the fever lasts or worsens.

Mostly, yes. The ice in your drink in Koh Samui is almost always factory-made from treated water and delivered in sealed sacks to bars and restaurants island-wide. The tube-shaped ice with a hole through the middle is the commercial kind. The bigger stomach risks are food left out in the heat, raw seafood, and unwashed hands.

Early signs of dehydration are thirst, dark yellow urine, a dry mouth, and a mild headache. In tropical heat you slide past these fast. Moderate signs include dizziness when standing, tiredness, and peeing very little. Severe signs such as confusion, a racing heart, or no urine for eight hours need medical care right away.

Dengue recovery time is two to four weeks for most people. The fever phase lasts two to seven days, followed by a critical window of one to two days as the fever drops, when doctors watch platelets closely. Energy then returns slowly, and tiredness lasting a few weeks is normal. Rest, fluids, and paracetamol only.