Recent Blog Articles
Does your child need to bathe every day?
Can flavonoids help fend off forgetfulness?
Can physical or cognitive activity prevent dementia?
Wondering how much your medical care will cost? New rules could help
Long-lasting healthy changes: Doable and worthwhile
The sore throat checklist: What parents need to know
A new treatment for obesity
Remember the flu? Yep, it's that time again
3 ways to build brain-boosting social connections
Grandparenting: Ready to move for family?
By the way, doctor: How can caffeine help migraines?
Q. If coffee constricts blood vessels, why would it help migraine sufferers, since the constriction curtails blood flow, which would seem to cause more pain?
A. The simple notion that migraines are caused by the expansion of blood vessels (vasodilation) on the surface of the brain is, well, too simple. Migraines are complicated. Abnormal brain activity may precede vasodilation, but I think vasodilation is probably responsible for the painful part of the migraine attack. Caffeine tends to constrict blood vessels, which would seem to cause pain by cutting off blood flow. But mid-migraine, caffeine may relieve pain by returning enlarged and painfully distorted arteries back to their pain-free state.
To continue reading this article, you must log in.
Subscribe to Harvard Health Online for immediate access to health news and information from Harvard Medical School.
- Research health conditions
- Check your symptoms
- Prepare for a doctor's visit or test
- Find the best treatments and procedures for you
- Explore options for better nutrition and exercise
I'd like to receive access to Harvard Health Online for only $4.99 a month.Sign Me Up
Already a member? Login ».
As a service to our readers, Harvard Health Publishing provides access to our library of archived content. Please note the date of last review or update on all articles. No content on this site, regardless of date, should ever be used as a substitute for direct medical advice from your doctor or other qualified clinician.