Any allergy or diet, understood in Thai.

Fish sauce (nam pla) as default seasoning · น้ำปลา (nam pla)

In Thailand, dishes that look vegetarian very often still contain fish sauce, oyster sauce, or shrimp paste, because cooks treat these as seasonings rather than meat. Saying only vegetarian is not enough; the local interpretation usually still allows fish sauce. Say no fish sauce (mai sai nam pla) and no oyster sauce, or look for the yellow and red เจ (Jay) symbol, which marks fully vegan food.

The vegetarian and vegan risk is the main one, but the same hidden ingredients matter for allergies too: fish sauce contains anchovy or fish, and shrimp paste and oyster sauce contain shellfish, so a fish or shellfish allergic traveler must not rely on a vegetarian label either. The เจ (Jay) symbol indicates fully vegan and is the safest signal.

Shrimp paste (kapi), the base in most Thai curry pastes and chili dips · กะปิ (kapi)

Thai shrimp paste (kapi) is made from fermented shrimp or krill and is a base ingredient in most Thai curry pastes (red, green, and others) and in nam phrik chili dips. So curries and even vegetable chili dips that look meat-free still typically contain shellfish, and anyone with a shellfish allergy should treat almost all Thai curries and nam phrik as unsafe unless confirmed kapi-free.

Kapi is made from shrimp or krill, both crustaceans, so it is relevant to shellfish allergy regardless of which is used. Wikipedia says it is in all Thai curry pastes while a curry-paste maker says most, so a few homemade or specialty pastes may omit it, but a shellfish-allergic traveler should assume it is present and confirm. Because it is hidden inside the paste, dishes that look meat-free or vegetarian commonly still contain it.

Pad thai · ผัดไทย (phat thai / pad thai)

Standard pad thai is not vegetarian or vegan even when it looks like a plain plate of noodles: it is typically flavored with fish sauce, has scrambled egg stir-fried in, and includes dried shrimp. It also carries peanut by default, since traditional versions mix in roasted peanuts. Ask for a dedicated vegan or vegetarian version and confirm no fish sauce, egg, dried shrimp, or peanuts.

Dried shrimp is standard in traditional pad thai but not strictly universal, since some shop versions omit it. Fish sauce, egg, and peanuts are near-universal in standard preparations. Vegan and vegetarian versions exist but must be ordered explicitly with fish sauce, egg, dried shrimp, and (for peanut allergy) peanuts all removed.

Pad see ew and dark soy sauce (see ew dam) · ซีอิ๊วดำ (see ew dam)

Pad see ew uses naturally gluten-free wide rice noodles, but the dish is defined by dark soy sauce (see ew dam), which is typically brewed with wheat and therefore contains gluten. The same wheat-based dark and light soy sauces season most Thai stir-fries, so the noodle being safe does not make the finished dish safe. Order pad see ew only where the kitchen confirms gluten-free soy sauce or tamari.

Not all Thai soy sauces contain wheat (some Thai brands use soybeans or rice without wheat, unlike most Chinese and Japanese soy sauces), but dark soy sauce specifically is brewed with wheat and gluten-free dark soy sauce is very hard to find. Treat dark soy sauce as wheat-containing unless a kitchen confirms otherwise.

Som tam (green papaya salad) · ส้มตำ (som tam)

Standard Central-Thai papaya salad (som tam Thai) is seasoned with fish sauce and lime, and typically pounded with dried shrimp and roasted peanuts. What looks like a plain raw-vegetable salad can hide fish, shellfish, and peanut at once. All three can be left out on request, but assume they are present unless you confirm otherwise.

Dried shrimp is sometimes listed as optional, and fish sauce, dried shrimp, and peanuts can all be omitted on request (substitute lime juice and sugar). Some versions also add shrimp paste. Assume all three allergens are present in the default dish unless confirmed otherwise. The Isan version (som tam pla ra) adds fermented fish, an additional fish source.