If Cenforce 100 mg contains sildenafil, flushing can occur because sildenafil causes vasodilation—it relaxes certain blood vessels, increasing blood flow. This can temporarily widen blood vessels near the skin, producing warmth or redness, particularly on the face, neck, or chest. Cenforce 100 mg is a recognized side effect of sildenafil. In clinical studies, it was reported in about 18% of people taking 100 mg, compared with 2% receiving placebo. The effect may be more noticeable in people who already have low blood pressure or take blood-pressure-lowering medicines because sildenafil's vasodilating effects can add to blood-pressure reduction. If flushing is severe, persistent, or occurs with fainting, chest pain, difficulty breathing, or significant dizziness, seek medical attention promptly.