10 Possible Side Effects Of Too Much Caffeine

By Ashley Henshaw. May 7th 2016

In today’s world, many people rely on caffeine to get them through the day.

Whether it comes from coffee, soda or chocolate, caffeine is a stimulant that is quickly absorbed by the body and travels to the brain, where it excites the brain and nervous system. This can be helpful in small amounts for the short-term relief of fatigue or drowsiness, but there can be some adverse side effects when too much caffeine is consumed. In this article, you’ll learn some of the potential side effects of ingesting too much caffeine.

Rapid Heart Rate

Because having caffeine excites your nervous system, it can put more pressure on your heart to keep up with this stimulated body state. As this happens, your heart rate may speed up to accommodate the extra work your body is doing. Having a rapid heart rate can be dangerous, especially for those who have a heart condition or suffer from irregular heart rhythms.

Difficulty Sleeping

Caffeine helps to keep you awake and alert, so it’s no surprise that having too much of it could interfere with your sleep patterns. It’s best not to have caffeine shortly before going to bed since this could keep you awake even longer. Even if you haven’t had caffeine recently, having a lot over the course of the day can still affect your ability to fall asleep at night. For some people, this produces a cycle where they don’t get enough rest at night, causing them to rely more on caffeine during the day.

For more information on sleep patterns, read: The Five Stages of Sleep.

Frequent Urination

Caffeine is a diuretic, which means that it helps your body get rid of fluids. This can lead to increased frequency of urination, especially when for individuals who get their caffeine fix through a drink like coffee, soda or tea.


The diuretic effects of caffeine may lead to nausea in some people as well. In some cases, people may even vomit after having too much caffeine, although people are more than likely to just feel nauseous, and actually vomiting is a very rare side effect.


People who drink too much caffeine may find that they experience headaches due to the stimulant’s effects on the brain. The pain may have varying levels of intensity and can be easily confused with other medical problems.


Some people do not deal well with the increased stimulation in their brain and nervous system, which can be the result of drinking caffeine. This could potentially lead to anxiety caused by the inability to deal with caffeine’s effects on the body. In more severe cases, some people even experience symptoms of depression from having too much caffeine.

Muscle Tremors

Many people experience some kind of body tremor or jitteriness after drinking too much coffee, which is a side effect of the overstimulation of the nervous system. Someone who stops consuming caffeine after having a long-term dependency on it might even suffer from withdrawals.

Decreased Bone Mass Density

Over time, consuming large amounts of caffeine may decrease a person’s bone mass density. It is believed the cause of this is the way in which caffeine interferes with the body’s ability to absorb calcium. In severe cases, a person with significantly decreased bone mass density could even develop osteoporosis.

Breast Lumps

People who drink too much caffeine could find that they are developing one or more painful lumps in their breasts, which is also known as fibrocystic disease. In some cases, simply cutting back on your caffeine intake will cause these lumps to disappear.


Children who have too much caffeine may not be getting adequate nutrition for proper growth and development. This is particularly true when a child has caffeinated drinks instead of healthy drinks like water, milk or juice. Additionally, caffeine could decrease the child’s appetite, which would increase the likelihood that they are not getting adequate nutrition in their diet.

Next Steps

  • According to the Mayo Clinic, heavy daily caffeine use is defined as more than 500 to 600 mg a day (or about six to eight cups of coffee). Remember to think of this as how many 8-ounce servings you consume as opposed to how many “cups” of coffee you fill up (some coffee shops sell serving sizes of up to 20 oz).
  • Though 500 to 600 mg is considered too much, that number may be slightly lower depending on your weight, age and other physical factors.
  • If you don’t drink caffeine regularly, you will be more likely to experience the side effects listed above when you do ingest this stimulant.
  • Although 200 to 300 mg is fine for most people, individuals with certain conditions may want to avoid caffeine or drink only a small amount each day. At-risk conditions for drinking caffeine include stress, anxiety, sleeping problems, acid reflux, stomach ulcers, irregular heart rhythms, high blood pressure, chronic headaches or fibrocystic disease. Additionally, women who are pregnant should only have very little or no caffeine.
  • If you are taking any prescription medications, be sure to ask your doctor about any potential negative interactions with caffeine.

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