Coffee is addictive, and those going through withdrawal often experience headaches and fatigue.

Coffee gives you energy, but it ultimately makes you more tired

The caffeine in coffee delays your brain's fatigue signals. Caffeine blocks adenosine, a compound that builds up as you burn energy and signals rest. Once caffeine wears off, adenosine floods back, leaving you even more tired.

Drug tolerance and withdrawals are consequences of overloading dopamine circuits

Addictive substances or behaviors will typically flood our brains with more dopamine than usual. In response to the overstimulation, our brains will decrease the number of available dopamine receptors. This results in the need for more stimulus for the same response (tolerance) and a rise in negative feelings when the stimulus is absent (withdrawal).

Addictive drugs can cause dopamine levels to become ten times higher than normal.

Coffee is, generally, good for your health

While overconsumption certainly has its drawbacks—hello, not sleeping until the sun rises—on the whole, coffee is fine, even beneficial, for your health. It can even help prevent serious health conditions, like heart attacks and liver cancer.

Up to 400 milligrams of caffeine a day is considered safe

Small, frequent doses can be more effective than large amounts, though caffeine can raise blood pressure and heart rate, especially in people with hypertension. While low doses of caffeine may help with depression by stimulating dopamine, excessive caffeine, particularly from energy drinks, can lead to anxiety and heart issues.

The American Heart Association says adults can safely drink up to five cups of coffee per day and regular consumption may improve cardiovascular health.

A caffeine calculator

This simple calculator takes your preferred caffeinated drink and your body weight to determine how much is the right amount, and how much might kill you. In case you've ever had the morbid curiosity about just how much of that tea you'd have to drink to doze off forever. Find out your moderate and lethal doses here, as well as some extra info on caffeine consumption.

Addiction is defined as chronic compulsive drug use despite adverse consequences

This resource from the National Institute on Drug Abuse provides a comprehensive look at addiction as a complex brain disorder. It explores why people initially take addictive substances and how continued use alters the brain’s reward system.

Coffee contains an average of 15mg of caffeine per fluid ounce

Coffee has three times the amount of caffeine contained in most caffeinated sodas, but significantly less than espresso and cocoa powder.

Bees are more likely to remember a flower if its nectar contains caffeine

Plants want pollinators to keep coming back, so the finding suggests that some plants, such as Citrus and Coffea species, have evolved to include caffeine in their nectar. Researchers suggest the findings could help develop methods to reinvigorate pollinator populations.

Addiction develops when the pleasure circuits in the brain get overwhelmed

Normal pleasure circuits become overwhelmed by addictive substances, triggering dopamine floods many times stronger than those induced by everyday reward experiences. The understanding of addiction as a brain disease has led to treatments pairing medication and counseling.

Chronic drug use can cause neurological changes in the brain

Neuroscientist Judy Grisel breaks down the biology of addiction, examining how drugs hijack the brain’s natural reward system and create lasting neural changes. The physiological and neurological impacts of chronic drug use require a multifaceted treatment approach.

Fame can trigger addictive, drug-like highs in the brain

Differences in the type of fame, such as movie stardom, sports, and internet virality, can produce varying degrees of dependence on individuals based on their age and background. Some individuals—particularly children—can develop drug-seeking behavior as they pursue continuous dopamine spikes if they lack an existing sense of fulfillment from elsewhere.

The brain will attempt to rest itself in periods of chronic sleep deprivation

Skimping on sleep lengthens reaction times and blunts decision-making skills. At a certain point, the brain will try to sneak sleep where it can, shifting sections offline even as you remain awake. Going without sleep raises blood pressure, undermines the immune system, and increases one's risk of dementia.

Your DNA may determine whether you like coffee or tea

Whether people prefer coffee or tea may boil down to a matter of taste genetics. People with a version of a gene that increases sensitivity to the bitter flavor of caffeine tend to be coffee drinkers, according to a report. Read on for more.

Distinct plant species evolved to produce caffeine as a pesticide

Although it provides a defense against insects trying to eat caffeine-bearing plants, the molecule is an example of exaptation, where its original function was repurposed over time. Studies show that some plants now produce caffeine-laced nectar to help pollinators move more quickly and pollinate more efficiently.

A major dopamine hit from social media use comes from unpredictability—not knowing if the content users post or share will get the 'like' from other users, triggering cycles of anticipation similar to those experienced with a slot machine.

'Susan's Brain': what happens to the brain during addiction

This engaging animation from Harvard Online breaks down the neuroscience of addiction through the story of “Susan’s brain,” demonstrating how addictive substances hijack normal reward pathways. Through clear visual metaphors and approachable narration, it explains complex brain chemistry in understandable terms.

The myth of sugar rushes vs. the reality of sugar crashes

It's generally accepted that sugar rushes are a myth, and that hyperactivity is a more psychological experience. However, there is real science behind the rare sugar crash that primarily impacts those with diabetes. Read this article to understand how historical and cultural factors have shaped sugar perceptions, and how low blood sugar can trigger shakiness, fatigue, weakness, and more in diabetes patients.

Why processed foods can be so addictive

In recent years, many critics have voiced their concerns about the food industry and how ultra-processed foods affect our health. Despite our awareness of these issues, processed foods are still incredibly hard to remove from our diet. In this podcast by The Guardian, Dr. Chris van Tulleken explains how “junk food” is created to get us hooked, how it negatively affects us, and what we can do to improve our eating habits.

How alcohol rewires your brain

Alcohol doesn't just make you tipsy—it rewires your brain chemistry in real time. It slows your brain with GABA, spikes dopamine to make you feel unstoppable, and blocks glutamate so you can't form memories. That mix explains everything from slurred speech to blackouts … and brutal hangovers.

What happens to your brain when you burn out?

You've probably heard of burnout, also known as the feeling of exhaustion that happens after a long period of being overwhelmed or stressed. It's often associated with work and careers, but other parts of life, like parenting, can cause burnout, too. Scientists are figuring out what happens, biochemically speaking, in the brain when burnout hits—and spoiler alert, it includes a neurotransmitter called glutamate. Watch this video to learn more.

Can the gut microbiome drive addiction?

New research suggests an imbalance of gut microorganisms may influence the likelihood of addiction and addictive behaviors by increasing the severity of withdrawal symptoms, triggering brain inflammation in regions of impulse control, and more.

Why the human brain loves opioids

When opioids enter the brain, they dock in receptors, blocking electrical pulses such as those that communicate pain. They also trigger the release of dopamine, a neurotransmitter tied to motivation and associated with stress relief.

Prolonged stress impairs the prefrontal cortex

Burnout isn't just a feeling—it physically affects the brain. Prolonged stress impairs regions of the brain responsible for decision-making, emotional control, memory, and more. It can also lead to chemical imbalances, like reduced dopamine and norepinephrine levels, that worsen these effects.

Most coffee is grown within the coffee belt, a geographic region characterized by mild climates, regular rainfall, and higher altitudes.

The history of coffee

From its likely origins in what is now Ethiopia to today's worldwide consumption, this video uses a map to show how coffee conquered the world. Follow along and see how pilgrimages and centuries of trade influenced the spread of the beverage we all know so well.

Delirium tremens is the most severe form of alcohol withdrawal

Due to the impact of alcohol on the central nervous system, withdrawal from the drug can cause severe effects. Roughly 1% to 1.5% of heavy drinkers will experience delirium tremens, which includes tremors, seizures, hallucinations, and more. Onset typically occurs 48-72 hours after the last drink.

Diabetes 101: Insulin deficiency leads to high glucose levels in the blood

Glucose, the brain's preferred energy source, enters the bloodstream when the body breaks down consumed carbohydrates. To manage this increase in readily available energy, the body releases the hormone insulin, which allows glucose to enter and fuel our cells. Without insulin, glucose remains in the blood, causing health issues.

Understand distinctions between coffee types and other popular cafe beverages with this visual guide.

Coffee is made by brewing the seeds from the coffeea plant

The cherries from the coffeea plant are milled into coffee beans. After processing, the beans are dried and roasted.

What happens to the brain during migraine?

Migraine is a neurological condition that can cause debilitating symptoms across various bodily functions. So, what exactly is happening in the brain during these attacks? This five-minute video briefly overviews the internal machinations behind the painful episodes. An incapacitating headache is a common symptom of migraine, though migraine can occur without any headache.

In the 1600s, coffee had religious significance

In the 1600s, coffee was important in multiple religious traditions. In Yemen, it was the drink of choice for Sufi mystics to improve their focus and fuel their grueling meditations. Pope Clement VIII's approval spread coffee’s popularity from the Muslim to the Christian world, paving the way for the cappuccino.

Emerging research suggests that cannabis, used by about 9% of American adults as a sleep aid, may suppress rapid eye movement and lead to worse quality sleep and fewer remembered dreams.

People are experiencing AI 'brain fry' at work

Workers, particularly in marketing, are experiencing mental fatigue in the workplace due to expectations—often unspoken—that they should use AI to multitask beyond their comfort levels. Many feel they are underperforming if they don't embrace this technology. This situation differs from typical burnout. This podcast discussion suggests that this "brain fry" tends to intensify when employees are required to use more than three AI tools.

The body produces its own opioids that act on several receptor types throughout the body, triggering the release of dopamine and suppression of noradrenaline, neurotransmitters associated with reward and alertness, respectively.

European colonization contributed to coffee's spread

European colonization created channels for large-scale coffee exports with workforces based in Asia, Latin America and the Caribbean. Trade routes throughout the Middle East and the rest of the world carried the drink to new shores and changed the agricultural and economic landscapes of the countries in the Bean Belt.

After the Boston Tea Party, colonists switched to coffee, which became the main morning drink for revolutionaries.

After the Boston Tea Party (1773), colonists boycotted tea and turned to coffee, with coffeehouses becoming hubs for revolutionary discussions. The stimulating import from the Caribbean helped shape the nascent American taste.

The negative effects of cannabis use

After decades of criminalization, cannabis is a legalized drug in an increasing number of countries around the world. This allows for accurate, robust research on the drug's effects on humans . While weed isn't as harmful as alcohol, regular usage has its negative effects. As strains of the drug become stronger, so does its consequences. Watch this video for a lucid look at the effects of cannabis on its users.

Narcolepsy occurs when the brain loses its ability to control its sleep-wake cycle.

Exercise releases chemicals that enhance cognitive function

Neurotransmitters like dopamine, serotonin, and norepinephrine, along with increased brain-derived neurotrophic factor levels, enhance a wide range of brain functions. New research demonstrates a direct link between movement and numerous cognitive benefits, including memory, learning, and stress resilience.

How to know if you're a workaholic

Are you a workaholic, or do you simply enjoy work? As it turns out, there's a big difference between putting in long hours at the office because you enjoy your job and actually having a work addiction. If you're reading this on hour 12 of your 14-hour workday and wondering which category you fall into, peruse this article to find out.

Stress and the brain

While an acute stress response is a normal bodily function, the effects of chronic stress can be extremely damaging to the human body. This is particularly true with regard to the brain. This article explores the effects of stress on the human brain, including how chronic stress may lead to psychological conditions such as depression and memory loss.

Alcohol use disorder is the most common addiction in the US

This comprehensive overview from the Addiction Center uses recent data from SAMHSA’s National Survey to examine the 10 most common substance dependencies in the United States. It ranks addictions from alcohol (affecting 28.3 million Americans) to barbiturates, while highlighting key trends, risks, and societal impacts.

Before it was a drink, coffee was used for handwashing.

Fentanyl is better at crossing the blood-brain barrier than other opioids

Among opioids, fentanyl is uniquely adept at crossing the blood-brain barrier—the brain's security fence against harmful substances. This enables a lightning-fast high. It ends just as quickly, sometimes within minutes (where a heroin high lasts hours), and still results in the same withdrawal symptoms.

Clinical burnout: prolonged exhaustion, mental distance, and persistent negative feelings

Burnout isn’t just stress—it’s a pervasive feeling of exhaustion that can start in the workplace and seep into everyday life. It causes feelings of dread and cynicism about work tasks. On top of emotional distress, there can be physical symptoms and a tendency towards addictive behavior.

What it's like to live with insomnia

The biological process Shakespeare referred to as the chief nourisher of life's feast is necessary for the body and mind to rest and repair from the activities of daily life. As sleep evades the exhausted, sufferers also lose emotional stability, mental clarity, social connections, and more while simultaneously gaining waves of interrupted biological processes that can lead to disease and death.

Key symptoms of burnout can be both mental and physical

Burnout can be accompanied by several symptoms, including low energy and chronic fatigue, trouble concentrating, difficulty sleeping, and depression. It may even manifest physically as musculoskeletal pain, headaches, stomach and intestinal pain, and more. More intense cases have been linked to cardiovascular and mental health disorders.

Is workaholism real?

Though work addiction is not officially recognized as a medical condition, it mirrors many patterns of other behavioral disorders. This exploration from BBC News examines the issue through Workaholics Anonymous, with a special focus on firsthand accounts from support group members.