When you reach for your morning cup of coffee, you can expect a few side effects. You may start to feel more alert and awake, which improves your concentration and prepares you for the day ahead. The caffeine in coffee is a stimulant, which speeds up your central nervous system and makes your heart beat more quickly. While a slightly faster heartbeat may not be dangerous to your health, a pounding heartbeat can be. Always speak to your physician if you repeatedly experience a pounding heartbeat or are concerned your symptoms may be a sign of an underlying condition.
How Caffeine Works
When you consume caffeine, it sets off a chain reaction to stimulate your brain, heart and lungs. Imagine this effect like the body's own version of the game "telephone." Caffeine first blocks the breakdown of a chemical messenger called phosphodiesterase, or PDE, according to "Scientific American." Because PDE breaks down a second messenger called cyclic adenosine monophosphate, or cAMP, this increases the amount of available cAMP in your body. The result is stimulation of neurotransmitters such as norepinephrine and epinephrine, also known as adrenaline. Norepinephrine in particular targets your heart, making your heart contract more forcefully and quickly. The result can be a heart that feels as if it is pounding.
Caffeine can affect different people in different ways, which may explain why you can drink an entire cup of coffee and not feel a single effect, while your friend seems on edge and wired. Men may be more susceptible to caffeine's effects than women, according to MayoClinic.com. Your response depends on how much you typically consume. For example, if you rarely drink a cup of coffee but have a large cup one day, you may likely experience heart pounding because your body is unaccustomed to the significant amount of caffeine.
If caffeine has a tendency to make your heart pound, chances are you may be taking in too much on a regular basis. For example, consuming between 500 and 600 milligrams of caffeine per day is associated with increased risk for a pounding heartbeat, irritability, stomach upset and nervousness, according to MayoClinic.com. This amount is roughly equivalent to five to eight cups of brewed coffee each day. To reduce the likelihood of these adverse effects, consume caffeine in moderation, which is about 200 to 300 milligrams of caffeine per day. This is roughly equivalent to two to four cups of brewed coffee a day.
Caffeine can start to take effect as soon as 15 minutes after it is consumed, according to the National Sleep Foundation. Your body takes about six hours to break down half the caffeine in your body, which means it may take some time for the heart-pounding effects to wear off. If you have other symptoms that could indicate a more serious condition, such as pain that extends down one arm, an inability to catch your breath, a pounding headache or loss of consciousness, seek immediate medical treatment. These can be the signs of a more serious condition and require medical attention.
Rachel Nall began writing in 2003. She is a former managing editor for custom health publications, including physician journals. She has written for The Associated Press and "Jezebel," "Charleston," "Chatter" and "Reach" magazines. Nall is currently pursuing her Bachelor of Science in Nursing at the University of Tennessee.