What health issue is typically treated with decongestants?

Decongestants are primarily used to relieve symptoms of respiratory congestion, which commonly occurs during colds, allergies, or sinus infections. They work by constricting the blood vessels in the nasal passages, reducing swelling and allowing for easier breathing. This is especially important when the body is dealing with excess mucus production due to inflammation in the respiratory system.

In contrast, headaches may be treated with analgesics rather than decongestants, as headaches usually involve different underlying causes. Abdominal pain and skin rashes involve medical issues that are not related to the respiratory system, thus requiring different treatments. Therefore, the specific focus of decongestants on alleviating respiratory congestion establishes why this is the most appropriate answer.