Almost always, sinus headaches occur with congestion. Nasal discharge is one of the most common symptoms of sinus. This happens due to the fact that the swelling and mucus block the sinuses and cause pressure to build up, thereby preventing proper airflow or drainage of the mucus. Since it’s rare to get a sinus headache without nasal congestion, it’s important to diagnose it with a doctor whether it’s a sinus headache or not.