Histamine receptors are members of the G protein-coupled receptor (GPCR) family, including four types: H1, H2, H3, and H4. They feature seven transmembrane helical structures and are distributed in various cells and tissues, such as neurons, smooth muscle cells, and immune cells. Histamine receptors activate various signaling pathways, such as cAMP, IP3/DAG, and MAPK pathways, participating in the regulation of inflammation, immune responses, gastric acid secretion, cardiovascular regulation, and neurotransmitter release. The specific expression of genes is associated with various diseases, such as allergic reactions, asthma, gastric ulcers, and sleep disorders. Mutations or expression changes affect their function, potentially leading to differences in disease development or treatment responses.