Could you tell me what are leads to of a headache?

Depends on the type: Of headache. Could be migraine, cluster headache, tension headache or others. The mechanisms for most headaches are poorly understood. There are many effective treatments available but an accurate diagnosis is required by a physician, like neurologist.

Identify triggers: There are certain foods and aspects of lifestyle that can trigger or worsen headaches and migraines. The best way to identify triggers is to maintain a headache diary and keep a list of foods eaten before your migraine. Common triggers include chocolate, caffeine, cheese, msg, processed meats, alcohol, smoking/being around smoke, stress, skipping meals, lack of sleep or too much sleep.