Headache is a common symptom, not a disease. It is safe to say that 90% of people have experienced a headache at some point in their lives. Headaches and insomnia are so closely related that we can use three specific manifestations of headaches to see how they affect sleep. The first type of headache is neuropathic headache. Known abroad as tension headache, the cause may be due to excessive contraction or spasm of the muscles at the top of the head, neck, or temporal region, or overwork or depressed mood. The pain is not severe, but it is uncomfortable, drowsy, and “not clear-headed”. It usually does not cause nausea or vomiting. The pain always worsens in the afternoon and then decreases in the evening, but the patient is relatively excited and often has anxiety, so it is common to have difficulty falling asleep. This condition was often diagnosed as neurasthenia in the past. The second type of headache is migraine. This type of headache is more common in young women and is a paroxysmal, episodic headache. The patient may have a visual aura before the headache, such as gold stars in front of the eyes, water ripples or battlement-like images, etc. After 20 to 30 minutes there is a severe headache, but the visual aura disappears. The headache can be located on one side or both sides, extending from the orbits and temples to the whole head, very intense, like fire, like a knife cut, like a throbbing blood vessel, as well as fear of light, fear of human voice, and nausea and vomiting in the most severe cases. Each attack lasts about 4 hours and up to 2 to 3 days. The interval between attacks varies from once a month to once every two to three months, but there are also attacks every week. Migraine with aura is called migraine with aura, and those without visual aura are called migraine without aura or common migraine. It is very difficult to sleep during migraine attacks, and often insomnia. Some patients can sleep with sleeping pills and the headache can disappear, so migraine and insomnia are closely related. The third type is called cluster headache. It is more common in strong males. This kind of headache often occurs in spring and autumn, and the attack time is quite fixed every year, such as the second week in October or the third week in March. The attacks occur in the middle of the night, and the pain is mainly on one side, so much so that the head is banged against the wall or the head is clutched on the ground, but the severe pain will suddenly disappear after 1 to 2 hours. Fortunately, each attack lasts only about 10 days, but it is enough to interfere with sleep.