When we are worried about our interlocutor, we saay
¿Qué te pasa? – What happens to you?
¿Estás bien? – Are you Ok?
When somebody looks like she is ill or tired we say
Tienes mala cara – You look bad
Te veo cansado – You look tired
Pareces triste – You seem sad
We can also advice her
Tienes que cuidarte – You should care
yourself
Tienes que tomarte un paracetamol – You should take a
paracetamol
A ver si te mejoras – I hope you´ll be better