The disorder is characterised by episodes of intense facial pain that usually last from a few seconds to several minutes or hours. The episodes of intense pain may occur paroxysmally. To describe the pain sensation, patients may describe a trigger area on the face, so sensitive that touching or even air currents can trigger an episode. It affects lifestyle as it can be triggered by common activities such as eating, talking, shaving and toothbrushing. The attacks are said by those affected to feel like stabbing electric shocks, burning, pressing, crushing, exploding or shooting pain that becomes intractable.
Individual attacks usually affect one side of the face at a time, lasting from several seconds to a few minutes and repeat up to hundreds of times throughout the day. The pain also tends to occur in cycles with remissions lasting months or even years. 10-12% of cases are bilateral, or occurring on both sides. This normally indicates problems with both trigeminal nerves since one serves strictly the left side of the face and the other serves the right side. Pain attacks typically worsen in frequency or severity over time. Many patients develop the pain in one branch, then over years the pain will travel through the other nerve branches.
Outwardly visible signs of TN can sometimes be seen in males who may deliberately miss an area of their face when shaving, in order to avoid triggering an episode. Successive recurrences are incapacitating and the dread of provoking an attack may make sufferers unable to engage in normal daily activities.