The caffeine connection between coffee and headaches


Dear Doctors: I am 69 years old and have two cups of coffee each morning. Once or twice a week, I wake up with a dull ache at the back of my head, toward the left side. It always goes away with my first cup of coffee. Is this caffeine withdrawal? My doctors have found no physical causes.

Dear Reader: Caffeine is a fascinating compound. For people who consume it regularly, its absence can trigger a headache. And because of the way the body responds to caffeine, its presence can sometimes relieve one. It’s possible that both of these things are occurring in your case.

Unfortunately, because headaches themselves are extremely complex, it is difficult to pinpoint their cause. Even with the CT scan that you said your doctors performed, they were unable to identify a reason for the intermittent headache you wake up with. What we can offer here is a discussion of caffeine and its effects on the human body. This includes what happens when someone consumes it regularly, and what can happen when they suddenly don’t.

Caffeine is a mild stimulant that is easily absorbed by the body. Depending on each individual, its effects can last up to 12 hours. As caffeine revs up the central nervous system, it can leave you feeling more awake and alert, deliver a boost of energy and help with focus and even mood. Caffeine also narrows blood vessels that surround the brain. That is its link to headache.

In some types of headaches, the blood vessels in the brain dilate, or swell. They expand into the surrounding tissues, which triggers pain. Consuming caffeine, which narrows the vessels, can ease or even reverse some headache pain. Ironically, a sudden lack of daily caffeine can cause a headache. It triggers a series of events that also lead to dilated blood vessels, and thus to headache pain.

Additional factors that can lead to a morning headache include too little or too much sleep, nighttime snoring, sleep apnea, high blood pressure, sinus congestion and dehydration. Some people find that a spike in sugar consumption, particularly later in the day, can be an overnight headache trigger.

Elizabeth Ko, MD and Eve Glazier, MD

If you’re willing to risk the effects of caffeine withdrawal, you can conduct a little experiment. Begin to gradually cut back your caffeine consumption over the course of a week or two. You can do this by drinking a bit less coffee each day, or by slowly swapping decaf for regular in your morning brew. As you systematically wean yourself from your habitual caffeine levels, you will be able to observe whether there’s a difference in the frequency of your occasional morning headaches. If you do see a change, this can help you pinpoint the amount of coffee you can drink without adverse effects.

It would not be surprising if a smaller amount proves easier to tolerate. As we age, our body’s ability to process caffeine changes. It’s common for older adults to have to make adjustments to their daily intake as the years go on.

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