What People whose immune systems overreact to foreign substances suffer from?

People whose immune systems overreact to foreign substances suffer from Allergies. In these cases, the immune system mistakenly identifies harmless substances, such as pollen or certain foods, as threats, leading to an exaggerated response. This can result in symptoms ranging from mild irritation, like sneezing and itching, to severe reactions, such as anaphylaxis. Conditions like Asthma and eczema can also be related to this overreaction of the immune system.