It Hurts
Use this to say 'I have pain'. It's a direct and very common alternative, especially in a medical context.
This is the equivalent of 'Ouch!' or 'Ow!'. Use it as an immediate reaction to sudden pain.
This means 'I hurt myself'. It's used to explain that you've just had an accident or injury.
This means 'It's sore'. Use 'adolorido' for masculine body parts (el brazo) and 'adolorida' for feminine ones (la pierna).
My head hurts.
Doctor, I have a stomach ache.
Ouch! I hit my knee.
I can't write well, I hurt my hand.
After the gym, my back is sore.
The phrase 'Me duele' is the universal and most understood way to express pain across the entire Spanish-speaking world.
'Me duele' is standard. You will hear it used identically to how it's used in Latin America. The verb conjugation changes for 'you all' (os duele), but this doesn't affect expressing your own pain.
'Me duele' is the primary phrase. It's common to add diminutives for emphasis, like 'Me duele un poquito' (It hurts a little).
While 'Me duele' is standard, you might hear the intensifier 're' added for emphasis in casual conversation: 'Che, me re duele el pie' (Man, my foot really hurts).
'Me duele' is common. In very informal contexts, you might hear slang for body parts, such as 'Me duele la guata' instead of 'Me duele el estómago' (My belly hurts).
Saying 'Yo duelo' instead of 'Me duele'. — The verb 'doler' (to hurt) works like 'gustar' (to like). The thing causing the pain is the subject. The literal structure is 'The head hurts me' ('La cabeza me duele'), which is why we say 'Me duele la cabeza'.
Saying 'Me dolor' instead of 'Me duele' or 'Tengo dolor'. — 'Dolor' is a noun meaning 'pain', while 'duele' is the verb 'it hurts'. You can 'have pain' ('tengo dolor') or something 'hurts you' ('me duele').
Using 'ser' for soreness, like 'Mi brazo es adolorido'. — Soreness is a temporary condition. For temporary states and conditions, always use the verb 'estar'. The correct phrase is 'Mi brazo está adolorido'.
Using the wrong pronoun, like 'Le duele la cabeza' when you mean 'My head hurts'. — You must use the correct indirect object pronoun: 'Me duele' (it hurts me), 'Te duele' (it hurts you), 'Le duele' (it hurts him/her/you formal).