¿Dónde está el problema?

1:21 

¿Dónde le duele?
Where does it hurt?

Enséñeme dónde le duele.
Show me where it hurts.

¿Le duele el pecho?
Does your chest hurt?

¿Tiene algún problema en el abdomen?
Do you have a problem in your abdomen?

We use algún / alguna before nouns when asking about the existence of something.

¿El problema está en su pierna derecha?
Is the problem in your right leg?

We use the verb ESTAR when referring to location (unless we are talking about an event). Spanish Grammar members see also: SE01 Ser y Estar – Location and State

¿El problema está en su brazo izquierdo?
Is the problem in your left arm?

Definite Article vs Possessive Adjective

3:12 

Although you can often use either a definite article or a possessive adjective before a part of the body, we more commonly use a definite article when it is clear whose body we are referring to. For example, 

¿Tiene algún problema en EL abdomen?

Here, the subject of the verb TENER = USTED. Therefore, it is clear that I am referring to the patient’s abdomen.

In the most recent examples, I chose to use the possessive adjective SU before the part of the body. For example,

¿El problema está en SU brazo izquierdo?

The subject of the verb ESTAR = EL PROBLEMA. Therefore, to be clear that I was referring to the patient’s left arm, I chose to use the possessive adjective, SU.

Note, in both of these examples, either a definite article or a possessive adjective would be correct. So don’t sweat it too much.