If you’re asking this question, you’re probably feeling something uncomfortable and persistent enough that you want a name for it. The short answer: stress and anxiety share many of the same physical sensations, but they differ in one critical way. Stress is a response to something specific happening in your life, and it fades when that situation resolves. Anxiety lingers even when there’s no clear cause, or it’s wildly out of proportion to the cause you can identify.
About 4.4% of the global population, roughly 359 million people, lives with a diagnosable anxiety disorder. It’s the most common mental health condition in the world. But not everyone who feels anxious has one. Here’s how to tell what you’re dealing with.
How Stress and Anxiety Actually Differ
Stress is your body’s emergency response to a challenge. A looming deadline, a fight with your partner, a medical bill you can’t pay. Your brain detects a threat and floods your system with cortisol and adrenaline, making your heart beat faster, your muscles tense, and your focus sharpen. This is useful. It helps you deal with the problem. And when the problem passes, the stress response winds down.
Anxiety borrows the same biological machinery but runs it without a clear off switch. The clinical definition draws a clean line: fear is a response to a real or imminent threat, while anxiety is anticipation of a future threat that may never arrive. You’re not reacting to something happening right now. You’re bracing for something that might happen, with the probability of actual harm being low or uncertain. Your body doesn’t know the difference, so it stays in that heightened state anyway.
This is why the two feel so similar physically. Sweating, rapid heartbeat, tight chest, upset stomach. Research shows that people can accurately detect when these symptoms are increasing or decreasing in their body, even if they can’t gauge exactly how intense they are. So if you feel like your heart is pounding more often than it should be, you’re probably right.
The Timeline Is the Biggest Clue
Psychologists distinguish between two types of anxiety: state and trait. State anxiety is a temporary spike, like the nervousness you feel before a job interview. It’s triggered by acute stress and fades once the situation ends. Trait anxiety is chronic. It shows up constantly across your life, regardless of circumstances, and it’s considered a stable part of how you experience the world.
If your worry is tied to a specific event (moving, a health scare, job loss) and you can imagine it easing once that event resolves, you’re likely dealing with stress. If your worry jumps from topic to topic, sticks around for weeks or months, and doesn’t seem to care whether things are objectively going well, that pattern looks more like anxiety.
For a clinical diagnosis of generalized anxiety disorder, the threshold is specific: excessive worry occurring more days than not for at least six months, about multiple events or activities, with difficulty controlling the worry. That six-month mark isn’t arbitrary. It’s designed to separate a rough patch from a pattern.
What Each One Feels Like Day to Day
Stress tends to feel like pressure. You know what’s causing it, and you can usually point to it: “I’m stressed about money” or “Work is overwhelming right now.” It can make you irritable, tired, or unable to sleep, but these symptoms track with what’s happening in your life. Remove the stressor, and you feel better relatively quickly.
Anxiety often feels like dread without a target. You might wake up with a knot in your stomach before you’ve even thought about the day ahead. You might find yourself catastrophizing, running worst-case scenarios about things that haven’t happened. Driving your kids to school turns into worrying you’ll be late to work, which turns into worrying you’ll lose your job, which turns into worrying about how you’ll pay rent. The chain of worry keeps extending beyond what the original situation warrants.
Physically, anxiety disorders tend to produce chronic symptoms rather than acute ones. A persistently upset stomach. Muscle tension that doesn’t let up. Trouble concentrating not because you’re busy, but because your brain won’t stop scanning for problems. Sleep disruption that persists even on weekends or vacation, when the external pressure is gone.
Triggers: External vs. Internal
One useful way to sort out what you’re experiencing is to trace where it starts. Stress almost always has an external trigger: a conflict, a change, a demand on your time or resources. When the trigger is removed or resolved, the feeling lifts.
Anxiety can be triggered externally too, but it’s also commonly set off by internal cues. A sudden feeling of abandonment when a partner pulls away. A wave of panic near a place where something bad once happened. A news headline that sends your mind spiraling for days. The trigger might seem small or even invisible to someone else, but your nervous system treats it as a five-alarm event. Over time, some people begin avoiding situations entirely, skipping social events or steering clear of anything that might set off the worry cycle.
What’s Happening in Your Body
Both stress and anxiety activate your body’s hormonal alarm system. Your brain signals the release of cortisol, the hormone that puts your body on high alert. In a healthy stress response, cortisol spikes, helps you deal with the threat, and then returns to baseline.
In anxiety disorders, this system tends to be overactive. Research consistently finds elevated baseline cortisol activity in people with anxiety, meaning the alarm system is partially firing even at rest. This helps explain why anxiety feels so physical: your body is genuinely in a different chemical state, not just your mind playing tricks on you. The fatigue, the muscle tension, the digestive problems are all downstream effects of a stress-hormone system that’s running too hot for too long.
Interestingly, anxiety and panic are driven by somewhat different biological pathways. Anxiety, which is about potential threats, leans heavily on cortisol. Panic, which is about perceived immediate danger, triggers a more intense adrenaline-driven response with less cortisol involvement. If your experience includes sudden, intense episodes of terror with a pounding heart and shortness of breath (as opposed to a slow background hum of worry), that distinction matters for how it’s treated.
A Quick Self-Check
Clinicians often use a seven-question screening tool called the GAD-7 to gauge anxiety severity. You can find it free online and take it in under two minutes. It asks how often in the past two weeks you’ve experienced things like uncontrollable worry, trouble relaxing, restlessness, and irritability. Scores break down into four levels:
- 0 to 4: Minimal anxiety
- 5 to 9: Mild anxiety
- 10 to 14: Moderate anxiety
- 15 and above: Severe anxiety
This isn’t a diagnosis. It’s a snapshot. But if you score in the moderate or severe range, it’s a concrete signal that what you’re feeling goes beyond ordinary stress. Even a mild score, if it persists week after week, is worth paying attention to.
Signs That What You’re Feeling Needs Attention
The clearest indicator that you’ve crossed from stress into something more serious is functional impairment, meaning the worry is interfering with your ability to do the things that matter to you. A few specific patterns to watch for:
- Social withdrawal: Pulling away from friends, family, or activities you used to enjoy.
- Sleep and appetite changes: Persistent disruptions that don’t resolve when your schedule calms down.
- Concentration problems: Falling behind at work or school not because of workload, but because your mind won’t cooperate.
- Emotional volatility: Increased irritability, frequent mood swings, or a growing sense of hopelessness.
- Avoidance behavior: Structuring your life around dodging situations that might trigger worry.
The diagnostic criteria for generalized anxiety disorder require three or more associated symptoms (restlessness, fatigue, difficulty concentrating, irritability, muscle tension, or sleep disturbance) present more days than not for six months. You don’t need to meet every criterion to benefit from support, but if several of these resonate and they’ve been going on for months rather than days, what you’re dealing with is likely more than stress passing through.