Immune system deficiency

Patient: I am a 18 year old female and keep getting sick.From a young age I’ve gotten cold sore very badly all over my mouth and inside my throat. It’s gotten better but now I get two at least once a month.I keep getting bronchitis so bad that I can’t breath.I can’t pick up weight since the age of 15.Must I do blood test to see if I have an immune system deficiency or what is wrong with me?I’m so tired of being sick…

Doctor: