This week I’m spending time in Colorado with my family and as usual, dealing with a migraine on arrival to altitude. Altitude headaches are not uncommon for both migraine headache patients as well as those who don’t suffer from migraines. There are 2 main issues that our heads need to deal with at altitude- oxygen deprivation and dehydration. Let’s talk about the effects of oxygen deprivation as a headache trigger.
At higher altitudes, the partial pressure of oxygen is lower than it is at sea level where many of us are used to living. Oxygen deprivation starts on the airplane, where the cabin is “pressurized” to supply a reasonable oxygen pressure, though not the normal pressure seen at sea level. Many of us get our migraines triggered just from flying and that is likely a combination of oxygen issues as well as the stress of making our flights and travel in general.
The brain is highly dependent on oxygen supply, which is why we faint when our blood pressure drops- the blood supply to the brain is critical for oxygen delivery. When the oxygen supply in the blood is normal but the delivery of the blood to the brain suddenly slows with low blood pressure, patients become unconscious and faint. When the blood supply is lowered less suddenly by a gentle decrease in blood pressure, such as when a patient takes nitroglycerin medication, a headache often ensues.
If the blood supply to the brain is normal, but the oxygen in the blood is low, similar conditions occur. In carbon monoxide poisoning from a house fire, for example, a sudden loss of oxygen supply can cause unconsciousness and tragedy. If, however, we are on the road behind an old car or bus spewing exhaust, we get a headache from the less sudden displacement of oxygen by the noxious gasses.
When I’m heading to the mountains, the lower oxygen supply on the plane and at altitude causes me to have a headache until I get used to things. In order to compensate for the oxygen difference at altitude, our blood changes over time to improve oxygen delivery to the brain. This is by two mechanisms- creation of more oxygen carrying red blood cells, as well as the production of something called DPG which allows oxygen to be released from the blood to the brain more easily. Those who live at altitude have more red blood cells, so their blood can carry more oxygen, and altitude becomes less of a headache trigger. (The increase in oxygen delivery also helps muscle performance, which is why endurance athletes train at higher altitudes.)
This post is long enough, so we will hold off on a discussion of dehydration for another time…. though I can give you a realistic hint of the effects of dehydration…. think hangover!
Wishing you a pain free week,
Dr. Lowenstein is a Board Certified Plastic Surgeon known for his meticulous techniques in both aesthetic and migraine surgery. Though his plastic surgery practice is in Santa Barbara at his Montectio Plastic Surgery Center, he loves to ski and cycle in the mountains of Colorado where he frequently vacations.