Headaches may occur from various causes; chiefly eye strain at work or study, Gas (flatulence), cold (flu conditions) from the heat of the sun, etc. Homeopathic medicines offer symptom-specific remedies as indicated by two doctors below

Source: 

• Dr. K.S. Gopi, Blog - ks-gopi dot blog spotdot com
• Dr. Umang Khanna, YouTube - सिर में दर्द || Headache || Natural homeopathic remedies with symptoms 

1. Belladonna 30 - the headache is of throbbing and bursting type, location forehead and temporal region (side of the head). The face is hot and the eyes fiery red, Eyes bloodshot and red, heavy dropping of eyelids and the face flushed. Headache is worse from light, noise, movement, or lying down. 2 drops thrice a day
2. Ruta 200 - headache from eye strain, from excessive computer screentime or reading, pain in forehead, pulsating type (frequent recurrence within small intervals of time). reduced eyesight due to strain, aching in eye with a burning sensation and redness
3. Carbo Veg 200 - headache from excessive flatulence/gas. In addition to headache, there is bloating in the abdomen, especially the upper abdomen. Belching (putrid, sour), and heartburn attend
4. Bryonia 30  - frontal headache of bursting and splitting type, hammer hitting type, headache occurs after having a haircut. Headache is worse from all movement even of the eyes and coughing. There is retching and bilious vomiting
5. Gelsemium 30 - dull, tired, and heavy type headache starts at the base of the neck and extends upwards,  drooping of eyelids, eyes heavy giddiness. The patient desires to lie with the head raised upon a high pillow and to be perfectly still for relief. Headache from mental labor and smoking tobacco. Headache is better from pressure and evacuation of pale urine.
6. Glonoine 30  - for congestive headache during menopause or due to suppressed menses. excellent remedy for headaches from sunstroke or exposure to bright light and heat. Violent throbbing headache due to high blood pressure. Face flushed. The headache is worse from every movement.
7. Ignatia 200 - a nervous type of headache after grief, exertion of mind like listening to a lecture or paying close attention to an orator. Headache as if a nail was driven into the head. The headache terminates with a profuse flow of urine.
8. Kali bich 3X  - headache due to sinusitis. Pain in the head in small spots due to suppressed catarrh. Headache over eyes, especially right eye. Before the headache comes on, the sight is blurred, the sight improving when the pain begins.
9. Natrum mur 200/1M - headaches begin at sunrise and wear away only after sunset, anemic headaches of school children. Headache as if thousands of little hammers were knocking on the brains, worse in the morning upon awakening It is also best for headaches from eye strain and during menstruation.
10. Melilotus 30 – headache relieved after epistaxis (blood flow from the nose) 2 drops 3 times a day
11. Nux Vomica 30 – headache after leaving stimulants like tea, coffee or alcohol. Headache occurs in the occiput or over the eyes with vertigo. There is a frontal headache with a desire to press the head against something. 2 drops 3 times a day

For best results, the medicines should match the indicated symptoms or as advised by your doctor

Dosage: (Pills) Adult and children 2 years of age and older: Dissolve 4 pills under the tongue 3 times a day until relieved or as directed by a physician. (Drops): Dr.Khanna suggests a typical dose of 2 drops of medicine 2-3 time daily. 

Related:

Headache medicine combinations suggested by experts like Dr.Pranjali and Dr. Kirti listed here