Large Intestine 4 is located at the highest point in the muscle belly on the medial side of where your thumb crease joins your hand (both hands). In this picture the exact point area would be closer down on the hand where the massager's thumbnail begins. Massaging this area, which may feel tender at first, is a great balancing point for headaches and migraines. Gently massaging the point and areas around it that feel tense or tender can help increase blood flow in the hand, along the Large Intestine Meridian and to the face which helps the body heal and clear stagnation. Each Acupunture point has many benefits for the body.
Precaution: If you are pregnant and experiencing a headache meeting with a practitioner would be most beneficial first.