Pressure in the forehead area is a common symptom of a tension headache, according to UCSF Medical Center. Poor posture, emotional stress and eyestrain can trigger tension headaches. Additional symptoms of a tension headache include scalp tenderness and neck pain.
Sinus inflammation can also trigger pressure across the forehead, according to Ear, Nose and Throat Associates of Corpus Christi. When the sinuses become inflamed due to colds, allergies or changes in air pressure, the nasal passages swell and secrete excess mucus. In addition to forehead pressure, sinus inflammation and swelling can also cause upper tooth pain and pain behind the eyes.