Use your Migraine.com account
Log in with Facebook
Log in with Google
Log in with Yahoo!Migraine pain on one side of the head: an introduction
Although migraines may cause pain all over the head, often the pain starts or is concentrated on one side. Pain on one side of the head is called unilateral pain. (When the pain is on both sides it is referred to as bilateral pain). More than half – about 59 percent – of migraine suffers complain that pain is on one side of the head according to the American Migraine Study II of almost 4,000 migraine sufferers in 1999.
In fact, the term migraine came from the Latin word hemicrania, which meant pain on one side of the head, or cranium. Some sufferers say the migraine attacks always happen on the same side, in others it may occur on either side and still there are those whose pain covers the head.
Studies have shown that the presence of pain on one side of the head is about the same whether the migraine occurs with or without aura – 58.1 percent for those with aura, and 60.3 percent for those without aura. Most studies include pain on one side of the head in the definition of migraine.
What happens to your brain when you have a migraine?
The answer varies depending on the person and sometimes varies with each migraine episode.
Frequently, migraine sufferers who experience migraine aura, a vision change that occurs in some before migraine pain, have one-sided pain. This may come from the changes in blood flow in the brain on one side, which scientists blame for aura and pain.
Uneven dysfunction in the brain stem may also be blamed for the one-sided migraine pain, according to a 2005 study that scanned the brains of patients as they suffered from a migraine. Researchers said the location of the disruption in brain function determines what part of the head hurts with migraines. The study found increased activity in part of the brain stem called the dorsolateral pons. For example, those with pain only on the right side of the head had more activity in the right side of the dorsolateral pons. The same was seen for those who only had pain from migraine on the left side, more action was seen on the left side of the brain stem.
Related articles & posts
Written by: Otesa Miles / Reviewed by: John-Claude Krusz, PhD, MD | Last review date: November 2010. Click the References Link below for a complete list of references.
Did you enjoy this article?
Read more just like it! Subscribe to the Migraine.com weekly and receive the latest migraine news and headlines, right in your inbox.
Find the information you're looking for
There are over 1,000 articles and stories on Migraine.com - but we have the tools you need to find the information most relevant to you.Hemicrania, Observations on 500 cases of migraine and allied vascular headache, JNNP, Selby 1960
Intrinsic brain activity…migraine model, Nature Medicine Bolay 2002
A PET study exploring the laterality... Brain, Afridi 2005
Migraine With and without aura: an epidemiological study, Cephalagia, Rasmussen 1992
Unilateral pain is part of migraine definition--Population Variation in Migraine Prevalence Meta Analysis, J Clin Epidemiology Stewart 1995
"I had my first migraine when I was 12. I thought I was going blind, the spots in my vision all grouped together and everything went black. The pain was intense and felt like my head would crack open above my right eye." 
Do you have migraines or tension-type headaches 15 or more days a month? Get the information and tools you need.
Download the free Migraine.com app for your phone and access your journal, headlines and more.