Caffeine
Caffeine is a stimulant in coffee, tea, chocolate, and energy drinks. It’s also found in prescription and over-the-counter medications. While caffeine can help improve alertness and concentration, it can cause negative side effects such as tension headache.
After taking a regular dose of caffeine, the body produces adenosine to suppress caffeine’s effects on the brain. This chemical then accumulates in the brain and spinal cord, causing muscle relaxation and drowsiness. When an excess of adenosine builds up in the system, it constricts blood vessels to slow down blood flow to the brain. The reduced blood supply causes a dull ache or throbbing pain on one or both sides of your head that may travel to your neck or shoulders.
The severity of these symptoms is directly related to your tolerance level. This may be influenced by your age, how fast you take the caffeine, whether you’re taking other stimulants simultaneously, or whether you have liver damage.
