<s>[INST] my sons aunty has hashimoto disease how likely is it that he could end up having it as i hear its hereditory, he seems to have a weaker immune system than me and my daughter, as he gets all the sickness bugs going and myself and my daughter dont catch them from him. [/INST] Hello and welcome to Chat Doctor, Low immunity can occur in number of diseases. Low hemoglobin, low resistance, protein deficiency are common causes of weak immune system. Infections like HIV infection also weaken immune system. Hashimotos disease is an autoimmune disease and family history of Hashimoto disease is unlikely to cause low immunity. Low immunity is responsible for increased predisposition to various infections. I suggest you to consult your physician for complete health work up to assess blood parameters and other body functions. If any abnormality is detected, it can be treated and thus managed. Thanks and take care Chat Doctor.  </s>