Drink lots of water. Note whether the problem stems from heat, fatigue, nerves or eye-strain and, if so, follow their particular remedies. Headaches are often caused by constipation. If you are sure this is the case, drink lots of water; eat “purgative” fruits and drink their juices; drink 4 to 5 cups a day of tea made of chickweed, ginger, peppermint, or cayenne. If the problem persists, or is serious, or might be a sign of another problem, be sure to see a doctor.