Receptor antagonists are substances that bind to specific receptors in the body but do not activate them. Instead, they block or inhibit the action of other molecules, such as hormones or neurotransmitters, that would normally trigger a response. This blocking action can help regulate various physiological processes and is often used in medical treatments. These antagonists are important in pharmacology and are commonly used to manage conditions like hypertension, anxiety, and allergies. By preventing the activation of certain receptors, receptor antagonists can reduce symptoms and improve patient outcomes, making them valuable tools in modern medicine.