There are several kinds of headaches, sometimes overlapping in cause and symptom. If you have headaches that are: increasing in frequency, last days not hours, and have other symptoms besides head pain, it's best to see your doctor and rule out health issues that can be serious. To address systemic causes of headaches, ask your doctor or naturopath about diet, blood pressure and and hormone testing. If you are under a lot of stress, consider seeking help like counseling, yoga, meditation, massage, etc. Addressing these factors will raise the threshold for getting headaches, making it less likely that tension and muscular imbalances will result in an intense headache.
Most headaches are entirely or partly caused by tension in the body. According to the Massage Therapist’s Guide to Pathology:
"By far the most common type of headache people experience (90-92%) is triggered by muscular tension, bony misalignment, postural patterns, eyestrain, temporomandibular joint disorders, myofascial pain syndrome, ligament irritation, or other musculosketetal imbalances. For the most common tension-type headaches, massage is resoundingly indicated. These episodes are an excellent opportunity to demonstrate how many seemingly disconnected postural and movement patterns can create pain in an entirely different area of the body."
Research has shown that in respect to tension headaches, massage can:
decrease perceived pain
decrease medication usage
Massage can help by releasing trigger points, which are tender areas of referring pain due to lack of blood flow to the muscle. While trigger point therapy is very helpful for relieving symptoms of a headache, most headaches are at their root postural issues (e.g. raised shoulders, forward head posture), as well as lifestyle (diet, coffee, exercise, sleep) and psychological (e.g. stress, clenching jaw). Some massage therapists may address the "common culprit" muscles, but these are usually only part of the whole picture. Orthopedic assessment of your upper body range of motion, posture education and structural integration can be life changing for someone with chronic headaches. It was for me. If you have headaches caused by whiplash, it will be essential to address strained neck muscles, as well as the entire whiplash disorder.
It's important to understand that during the time a person is suffering from a headache, a massage designed to treat the underlying myofascial causes and resulting trigger points will possibly exacerbate the symptoms. The system is already in a sensitized state. Gentle acupressure on the neck/shoulder area and light calming massage the rest of the body and will likely be more palliative. This is why I advise people to wait until they are not experiencing a headache unless they just want to relax and have some symptom relief - we will not be able to address the root causes during the headache episode.
Besides massage specifically for headaches, here are some other things you can do to speed and increase odd of recovery:
see a doctor or naturopath to identify underlying causes, including: diet, hormones, and blood pressure