The cause of migraines is similar to that of cluster headaches, but the intensity of pain is lesser. It will often be characterised by tingling or pinching sensations, throbbing pain or swelling pain. Some patients receive no relief from strong pain killers. Chinese medicine practitioners believe that the cause of migraines stem from the toxins in the liver, resulting in an imbalance in the contracting and expanding of the blood vessels in the brain. Chinese medicine practitioners use acupuncture and herbal medicine to balance the function of the liver to treat migraines.