Common Illnesses Travellers Face in Vietnam

Most people who visit Vietnam are not ill at any point. The country is not particularly dangerous health-wise. But a few things turn up often enough to be worth knowing about in advance, so you do not panic when they happen.

This is a layperson's overview, not medical advice. For diagnosis and treatment, see a doctor.

Traveller's diarrhoea

The classic one. Despite reputation, Vietnam is not Mexico — most visitors who eat at busy, popular places, with food cooked hot in front of them, are fine. The cases that go wrong almost always trace to one of three things:

• Iced drinks at low-traffic stalls — machine-made block ice is safe; crushed ice of unclear origin is not.
• Raw herbs and salads at quiet venues — washing standards drop when nobody is watching.
• Reheated buffet food sitting in warm bain-maries, especially at hotel breakfasts in low season.

A loose stomach in week one is normal even with no specific cause — your gut flora is adjusting. Stay hydrated with oral rehydration salts (Oresol or Hydrite, every pharmacy), eat plainly (rice, bananas, plain noodles), avoid alcohol and dairy for a couple of days.

If you have a fever above 38.5°C, blood in stool, more than six watery stools a day, or it lasts beyond 72 hours, see a doctor. Do not start antibiotics on your own even though Vietnamese pharmacies will sell them — wrong drug for the wrong bug is worse than nothing.

See water and food safety and street food etiquette.

Respiratory issues

Air quality is the underrated health story in urban Vietnam. Hanoi has serious winter air pollution — between November and March, AQI regularly tops 200 and occasionally goes past 300. Ho Chi Minh City is better but not great. Da Nang and the coast are generally fine. Rural areas are usually fine except during stubble-burning season.

Symptoms: sore throat, dry cough, sinus congestion, mild eye irritation. People with asthma flare up here who do not at home. Bring your inhaler. A KN95 or N95 mask helps; surgical masks do not. Run an air purifier in your hotel room if you are staying a while in Hanoi — many serviced apartments now provide them on request.

For acute respiratory infection — fever, productive cough, breathlessness — see a doctor rather than self-treating. Pneumonia is common in older travellers after pollution exposure.

Heat exhaustion

Vietnam is hot and humid, particularly April through September in the south and centre. Heat exhaustion is more common than people expect, especially among visitors who arrive from cooler climates and try to do too much on day one.

Symptoms: heavy sweating, weakness, dizziness, nausea, headache, fast pulse. The fix is to get into shade or air-conditioning, lie down, drink electrolyte solution slowly. People typically recover within an hour.

Heat stroke — confusion, hot dry skin, body temperature above 40°C — is a real emergency. Cold pack the armpits and groin, get to A&E.

See the dedicated heat and sun guide for prevention.

Fungal skin and ear infections

Humidity plus sweat plus tight clothing equals fungal rash. Athlete's foot, jock itch, and "fungal acne" on the back and chest are extremely common in summer. Local pharmacies stock clotrimazole, ketoconazole, and miconazole creams cheaply.

Swimmer's ear (otitis externa) is common after pool and sea swimming. A few drops of half-and-half white vinegar and rubbing alcohol after swimming prevents most cases. If your ear is sore, blocked, and discharging, see a doctor.

Skin issues from heat rash and bites

Heat rash (miliaria) — pinprick itchy red bumps where clothing rubs — clears in a day or two with looser clothes and a cool shower. Mosquito bite reactions are often more pronounced here, partly because Aedes saliva is stronger and partly because you may be getting bitten more than you realise. Local Soffell or Remos repellents help.

For raised, hot, expanding redness around a bite or scratch — that is cellulitis, see a doctor. Tropical wounds infect faster than you expect.

When to skip self-care and see a doctor

• Fever above 38.5°C lasting more than 48 hours.
• Any severe pain — abdominal, chest, headache.
• Vomiting that prevents you keeping liquids down.
• Any sign of infection in a wound — pus, spreading redness, fever.
• Confusion, severe weakness, fainting.

For doctors, see hospitals by city. For medications, pharmacies and medication.