TL;DR While caffeine has various health benefits, having too much has its downsides too. This article lists down various signs and symptoms that you may be having one too many cups of joe.
Do you find yourself heading to the coffee-maker straight from bed? Then you’re one of 62% Americans who drink coffee every single day.  Call it a morning ritual or a habit that can’t be shaken, but it’s pure unadulterated java love.
Some, however, call it caffeine addiction.
Of the American adults who take caffeine daily, half or more of them are subject to caffeine withdrawal symptoms when they don’t get a fix (more on this later).
When you have your daily caffeine fix for a long period (we’re talking about years here), your brain chemistry and receptiveness to the stimulant changes.  What happens is that because caffeine mimics adenosine, your brain tries to keep up with the additional “adenosine” by creating more receptors. As a result, your brain tells your body to “want” more caffeine to fill up these vacant receptors - a.k.a. you wanting more caffeine.
And if you suddenly halt your caffeine intake, then you’re in for some adventure... an unpleasant one at that.
Quitting cold turkey is like signing up for seemingly eternal feelings of tiredness, and other symptoms of caffeine withdrawal. 
Caffeine withdrawal symptoms may strike people who have doses as low as 100 milligrams a day. That’s equal to about 6 ounces of brewed coffee or two cans of soda. Experiments have shown that about half regular drinkers of coffee or consumers of caffeine in other products get withdrawal headaches when they abstain.
“When all withdrawal symptoms are considered, the incidence of caffeine withdrawal is higher,” the Johns Hopkins states. “In a population-based random digit dial telephone survey study, 40 to 70% of individuals who tried to quit caffeine use reported experiencing withdrawal symptoms.
While caffeine has various health benefits, having too much has its downsides too.
You know when you’ve gone overboard when: first, you’ve had more than the required daily intake. Here’s how much caffeine you should have in a day.
Second sign? When you start getting symptoms of caffeine addiction, like the following: 
According to the Journal of Caffeine Research in its DSM-5 Caffeine Use Disorder diagnosis, “a number of recent clinical studies show that a nontrivial proportion of caffeine users develops clinically meaningful features of caffeine dependence, including a persistent desire or unsuccessful efforts to cut down or control caffeine use, continued use despite harm, and a characteristic withdrawal syndrome.” 
In non-scientific terms, this means that there are clinical signs to watch out for among caffeine lovers before they can be considered “caffeine addicts” suffering from Caffeine Use Disorder (CUD).
Here are 6 ways to tell whether someone is suffering from CUD, who often show the first three signs in a span of 12 months:
1. A persistent desire or unsuccessful efforts to cut down or control caffeine use.
According to the aforementioned research, caffeine shows addictive properties that are similar in effects with cocaine and amphetamines. Caffeine is said to produce this addictive effect from dopamine (happy hormones) release. Those who suffer from caffeine addiction are reported to have identified themselves to liking the drug and enjoying a heightened feeling of wellbeing.
2. Continued caffeine use despite knowledge of having a persistent or recurrent physical or psychological problem that is likely to have been caused or exacerbated by caffeine.
Researchers say this is due to reinforcement, which “influences rates of operant behavior, including drug use.”
Said research defines reinforcement as:
Reinforcement is an essential behavioral mechanism that influences rates of operant behavior, including drug use. A drug is said to function as a reinforcer when drug administration increases the future likelihood of drug use (e.g., increased drug self-administration or increased choice of drug over placebo).
According to related research, low to moderate doses of caffeine “have been shown to function as reinforcers in both human and nonhuman animal subjects” [6,7,8] and especially for those with a “history of heavy caffeine use.” 
These findings are supported by evidence such as subjects consistently picking caffeine over placebo and avoiding withdrawal symptoms.
The research defines caffeine withdrawal as:
“… a time-limited syndrome that develops after cessation of chronic (e.g., daily) caffeine administration. Caffeine withdrawal has been shown to occur in a range of nonhuman animal species, and a clearly defined caffeine withdrawal syndrome has also been well documented in humans.”
It also defines common symptoms of withdrawal as follows:
Related article: What are caffeine withdrawal symptoms and how to reduce them
The research adds that withdrawal usually manifests as either of the following:
a. The characteristic withdrawal syndrome for caffeine.
b. Caffeine (or a closely related substance) is taken to relieve or avoid withdrawal symptoms.
4. Caffeine is often taken in larger amounts or over a longer period than was intended.
Experts highlighted how caffeine users eventually develop tolerance both physiologically and behaviorally, leading caffeine addicts to ingest increased doses over time. The research defines tolerance as:
Tolerance to caffeine occurs when the physiological, behavioral, and/or subjective effects of caffeine decrease after repeated exposure to the drug, such that the same dose of caffeine no longer produces equivalent effects, or a higher dose of caffeine is needed to produce similar effects.
An important caveat is that tolerance does not develop in low doses, only after “chronic administration of very high doses of the drug (i.e., 750–1200 mg/day).”
The research further describes tolerance as either of the following:
a. A need for markedly increased amounts of caffeine to achieve the desired effect.
b. Markedly diminished effect with continued use of the same amount of caffeine.
5. Recurrent caffeine use resulting in a failure to fulfill major role obligations at work, school, or home
The research describes a clinical sign of caffeine addiction also involves significant adverse implications in day-to-day activities such as being late or absent from daily obligations, i.e work or school.
6. Continued caffeine use despite having persistent or recurrent social or interpersonal problems caused or exacerbated by the effects of caffeine
Another clinical sign of caffeine addiction is its impact on interpersonal relationships. This may include but not be limited to family conflicts, disagreements with friends and co-workers, and the like. Caffeine intake is seldom attributed to such conflicts though, “given the wide availability and social acceptance of caffeine use.” In fact, the Drug and Alcohol Dependence study reported a meager 2% of subjects reported caffeine use in spite of interpersonal issues.
7. A great deal of time is spent in activities necessary to obtain caffeine, use caffeine, or recover from its effects.
8. Craving or a strong desire or urge to use caffeine.
Johns Hopkins Medicine’s Behavioral Pharmacology Research Unit calls caffeine the most common mood-altering substance used in the world: 
The mood-altering effects of caffeine depend on the amount of caffeine consumed and whether the individual is physically dependent on or tolerant to caffeine. In caffeine non-users or intermittent users, low dietary doses of caffeine (20-200 mg) generally produce positive mood effects such as increased well-being, happiness, energetic arousal, alertness, and sociability. Among daily caffeine consumers, much of the positive mood effect experienced with consumption of caffeine in the morning after overnight abstinence is due to suppression of low-grade withdrawal symptoms such as sleepiness and lethargy (see section on Caffeine Withdrawal). Large caffeine doses (200 mg or greater) may produce negative mood effects. Although generally mild and brief, these effects include increased anxiety, nervousness, jitteriness, and upset stomach. However, individual differences in sensitivity and tolerance affect the severity and likelihood of experiencing negative effects.
People who consume caffeine may be unaware of their physical dependence on the chemical because they get caffeine every day. Also, low doses, as little as 25 mg, can prevent withdrawal symptoms from occurring. So a caffeine “addict” may forego his usual three cups of coffee but get enough caffeine from a chocolate bar or energy bar to forestall the worst symptoms.
“Thus, some people may report never experiencing withdrawal because they unknowingly consumed small amounts of caffeine on days they thought they had been caffeine free. Finally, caffeine withdrawal symptoms (e.g., headache, nausea, muscle aches) may be misattributed to other causes or ailments (e.g., viral infection),” Johns Hopkins states.
Viter Energy doesn’t want to seem alarmist about caffeine. We love it.
Some believe it's more of dependence than an addiction, though.
According to WebMD, caffeine only causes a mild physical dependence.  To be termed as addictive, it must pose a threat to your physical, social, occupational, or economic health.
Caffeine is a stimulant to the central nervous system, and regular use of caffeine does cause mild physical dependence. But caffeine doesn’t threaten your physical, social, or economic health the way addictive drugs do. (Although after seeing your monthly spending at the coffee shop, you might disagree!)
If you stop taking caffeine abruptly, you may have symptoms for a day or more, especially if you consume two or more cups of coffee a day. …
No doubt, caffeine withdrawal can make for a few bad days. However, caffeine does not cause the severity of withdrawal or harmful drug-seeking behaviors as street drugs or alcohol. For this reason, most experts don’t consider caffeine dependence a serious addiction.
The good news is caffeine does not threaten consumers’ health as far as cancer, heart disease or reproductive problems, though some types of coffee have lipids that may raise cholesterol. Also there may be a link between taking large amounts of caffeine and delayed conception and lower weight of babies at birth.
People may want to try to quit caffeine for several reasons. Some don’t want to have to be tied to a routine where they must get their two or three cups of java, tea or soda at certain times of the day. Others may balk at being classified as an addict of any kind. Still, others may be pregnant and don’t want to risk their baby being underweight at birth.
If you want to cut the caffeine out of your diet, CaffeineInformer.com has some tips on getting off of it: 
If you think that you may be too dependent or even addicted to caffeine, don’t fret. Recognize that many people experience the same and that solutions are available.
Caffeine in itself is not a health threat to humans. The important thing is awareness and intentionality. Know how much caffeine your body can consume and be mindful of your daily caffeine intake.
If you’re not sure how much caffeine you should have in a day, then this article is perfect for you.
Should you decide to slow down on your caffeine intake, then why don't you start with a having a pop of caffeine mint instead of ordering your next venti latte? Viter Energy Mint has 40 mg of caffeine so you're sure not to go overboard with your caffeine intake!
As we said in this Viter Energy blog  about the work-life balance, it's a good idea to simulate your commute to work. You don't have to drive in to work, so instead take a walk around the block just before your workday starts and just after it ends. Send yourself a psychological signal.
And if you can avoid it, do not work after your walk around the block. Don't check work email. Don't answer calls from co-workers unless you really need to talk to them (or they are friends you socialize with).
Clinical psychologist Kelcey Stratton of Michigan Health Blog  has some sound advice on finding the right time to work:
If you’re a morning person, try to schedule important work and meetings during the first half of the day. Others may peak with energy in the afternoon. Depending on the type of job you have, try to maximize on these levels as you can.
The first bit of advice is to get up from the computer, turn off your phone, and go get some exercise, do something recreational, prepare a meal, or something other than work, on the same schedule as you did when you worked at the brick-and-mortar office.
If you used to get off at 5 p.m., quit working at home at 5. You might need to check email or prepare a report later that night, but be sure to get away from all electronic communications and computing devices for a while.
Another big tip is to take your coffee breaks and lunch breaks on the same schedule, or at least be sure to take them at some point. Do not skip your favorite part of the day!