Final answer:
The purpose of H1 antihistamines is to block the H1 receptors, preventing allergic symptoms like itching and sneezing, and treat related conditions such as insomnia and motion sickness. These drugs provide short-term relief and are differentiated from H2 antihistamines, which treat gastric conditions.
Step-by-step explanation:
H1 antihistamines are medications that primarily block the histamine H1 receptors, which are responsible for causing allergic symptoms such as itching, runny nose, and sneezing. By doing so, they help alleviate these uncomfortable reactions. When histamines are released by mast cells during an allergic response, they bind to H1 receptors in various parts of the body, including smooth muscle and endothelial cells, leading to the symptoms of an allergic reaction. H1 antihistamines can also be effective in treating conditions like insomnia, motion sickness, or vertigo.
Antihistamines are not long-term solutions but are usually effective for short-term relief. People who experience chronic allergies, which can lead to more serious conditions like asthma or sinusitis, should consult a medical professional before long-term use of antihistamines. Finally, H1 antihistamines should not be confused with H2 antihistamines, which are used to treat gastric acid conditions like peptic ulcers and acid reflux by targeting the H2 receptors in the stomach.