Hi I think it is cluster headache. It is producing tearing of eyes, bad unilateral headache, daily happens at night. Another characteristic of cluster headache is that the attacks happen for a few days or weeks and then there are months without any episode. The symptoms may also be noticed like restlessness, facial flushing, fear of going to sleep, photophobia, aura, etc. Many of these headaches last for 15 min to 3 hours. Oxygen and sumatriptan may be used to abort an acute attack. Dihydroergotamine is also employed to reduce the intensity of attack. Verapamil, a calcium channel blocker, or sumatriptan orally are usually prescribed for prophylaxis. It is important that the patient is aware of the triggers and avoids them. The usual triggers like smoking and alcohol should be avoided. He should also keep a headache diary. Dr Vaishalee